Energy Conservation Program: Energy Conservation Standards for Small Electric Motors
Federal RegisterMar 9, 2010
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DEPARTMENT OF ENERGY
10 CFR Part 431
[Docket Number EERE-2007-BT-STD-0007]
RIN 1904-AB70
Energy Conservation Program: Energy Conservation Standards for Small Electric Motors
AGENCY:
Office of Energy Efficiency and Renewable Energy, Department of Energy.
ACTION:
Final rule.
SUMMARY:
The U.S. Department of Energy (DOE) is adopting energy conservation standards for small electric motors. DOE has determined that these standards will result in significant conservation of energy, and are technologically feasible and economically justified.
DATES:
Effective Date:
The effective date of this rule is April 8, 2010. The standards established in today's final rule will be applicable starting March 9, 2015.
ADDRESSES:
For access to the docket to read background documents, the technical support document, transcripts of the public meetings in this proceeding, or comments received, visit the U.S. Department of Energy, Resource Room of the Building Technologies Program, 950 L'Enfant Plaza, SW., 6th Floor, Washington, DC 20024, (202) 586-2945, between 9 a.m. and 4 p.m., Monday through Friday, except Federal holidays. Please call Ms. Brenda Edwards at the above telephone number for additional information regarding visiting the Resource Room. (Note: DOE's Freedom of Information Reading Room no longer houses rulemaking materials.) You may also obtain copies of certain previous rulemaking documents in this proceeding (
i.e.,
framework document, notice of public meeting and availability of preliminary technical support document, notice of proposed rulemaking, draft analyses, public meeting materials, and related test procedure documents from the Office of Energy Efficiency and Renewable Energy's Web site at
http://www.eere.energy.gov/buildings/appliance_standards/commercial/small_electric_motors.html).
FOR FURTHER INFORMATION CONTACT:
Mr. James Raba, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, EE-2J, 1000 Independence Avenue, SW., Washington, DC 20585-0121, (202) 586-8654, e-mail:
Jim.Raba@ee.doe.gov.
Mr. Michael Kido, U.S. Department of Energy, Office of General Counsel, GC-72, 1000 Independence Avenue, SW., Washington, DC 20585, (202) 586-8145, e-mail:
Michael.Kido@hq.doe.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Summary of the Final Rule and Its Benefits
A. Energy Conservation Standards Levels
B. Benefits and Burdens to Customers of Small Electric Motors
C. Impact on Manufacturers
D. National Benefits
E. Conclusion
II. Introduction
A. Authority
B. Background
1. Current Energy Conservation Standards
2. History of Standards Rulemaking for Small Electric Motors
III. General Discussion
A. Test Procedures
B. Technological Feasibility
1. General
2. Maximum Technologically Feasible Levels
C. Energy Savings
D. Economic Justification
1. Specific Criteria
a. Economic Impact on Motor Customers and Manufacturers
b. Life-Cycle Costs
c. Energy Savings
d. Lessening of Utility or Performance of Equipment
e. Impact of Any Lessening of Competition
f. Need of the Nation to Conserve Energy
g. Other Factors
2. Rebuttable Presumption
IV. Methodology and Discussion of Comments on Methodology
A. Market and Technology Assessment
1. Definition of Small Electric Motor
a. Motor Categories
b. Horsepower Ratings
c. Performance Requirements
d. Motor Enclosures
e. Frame Sizes
f. Insulation Class Systems
g. Service Factors
h. Metric Equivalents and Non-Standard Horsepower and Kilowatt Ratings
i. Summary
2. Product Classes
B. Screening Analysis
C. Engineering Analysis
1. Product Classes Analyzed
2. Baseline Models
a. Baseline Efficiencies
b. Baseline Temperature Rise
c. Baseline Motor Performance
3. Higher Efficiency Motor Designs
a. Electrical Steel
b. Thermal Analysis
c. Performance Requirements
d. Stray Load Loss
e. Stack Length and Core Diameter
4. Cost Model
5. Efficiency Scaling
6. Cost-Efficiency Results
D. Markups to Determine Equipment Price
E. Energy Use Characterization
1. Applications
2. Annual Hours of Operation and Motor Loading
F. Life-Cycle Cost and Payback Period Analysis
1. Installation Cost
2. Energy Prices
3. Energy Price Trend
4. Maintenance and Repair Costs
5. Equipment Lifetime
6. Discount Rates
7. Space-Constrained Applications and the After-Market
8. Standard Compliance Date
G. National Impact Analysis—National Energy Savings and Net Present Value Analysis
1. General
2. Shipments
3. Space Constraints
4. Base-Case and Standards-Case Efficiency Distributions
5. Annual Energy Consumption per Unit
H. Customer Sub-Group Analysis
I. Manufacturer Impact Analysis
1. Capital Conversion and Equipment Conversion Costs
2. Manufacturer Selling Prices
3. Markup Scenarios
4. Premium Electrical Steels
J. Employment Impact Analysis
K. Utility Impact Analysis
L. Environmental Assessment
M. Monetizing Carbon Dioxide and Other Emissions Impacts
1. Social Cost of Carbon
a. Monetizing Carbon Dioxide Emissions
b. Social Cost of Carbon Values Used in Past Regulatory Analyses
c. Approach and Key Assumptions
2. Monetary Values of Non-Carbon Emissions
V. Discussion of Other Comments
A. Trial Standard Levels
B. Enforcement
C. Nominal Full-Load Efficiency
VI. Analytical Results and Conclusions
A. Trial Standard Levels
B. Significance of Energy Savings
C. Economic Justification
1. Economic Impact on Motor Customers
a. Life-Cycle Costs and Payback Period
b. Life-Cycle Cost Sensitivity Calculations
c. Customer Subgroup Analysis
d. Rebuttable Presumption Payback
2. Economic Impact on Manufacturers
a. Industry Cash-Flow Analysis Results
b. Impacts on Employment
c. Impacts on Manufacturing Capacity
d. Impacts on Subgroups of Manufacturers
e. Cumulative Regulatory Burden
3. National Net Present Value and Net National Employment
4. Impact on Utility or Performance of Equipment
5. Impact of Any Lessening of Competition
6. Need of the Nation To Conserve Energy
7. Other Factors
D. Conclusion
VII. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act
D. Review Under the National Environmental Policy Act
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under the Treasury and General Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under the Information Quality Bulletin for Peer Review
M. Congressional Notification
VIII. Approval of the Office of the Secretary
I. Summary of the Final Rule and Its Benefits
A. Energy Conservation Standards Levels
The Energy Policy and Conservation Act, as amended (42 U.S.C. 6291
et seq.;
EPCA or the Act), directs the U.S. Department of Energy (DOE) to adopt energy conservation standards for those small electric motors for which standards would be technologically feasible and economically justified, and would result in significant energy savings (42 U.S.C. 6317(b)(1)-(2)). The standards in today's final rule satisfy these requirements and will achieve the maximum improvements in energy efficiency that are technologically feasible and economically justified. Table I.1 and Table I.2 show these standard levels, which will apply to all small electric motors manufactured for sale in the United States, or imported into the United States, starting five years after publication of this final rule.
Table I.1—Standard Levels for Polyphase Small Electric Motor
Motor output power
Six poles
Four poles
Two poles
0.25 Hp/0.18 kW
67.5
69.5
65.6
0.33 Hp/0.25 kW
71.4
73.4
69.5
0.5 Hp/0.37 kW
75.3
78.2
73.4
0.75 Hp/0.55 kW
81.7
81.1
76.8
1 Hp/0.75 kW
82.5
83.5
77.0
1.5 Hp/1.1 kW
83.8
86.5
84.0
2 Hp/1.5 kW
N/A
86.5
85.5
3 Hp/2.2 kW
N/A
86.9
85.5
* Standard levels are expressed in terms of average full-load efficiency.
** These efficiencies correspond to a modified Trial Standard Level 4b for polyphase motors. For horsepower/pole configurations with efficiency standards higher than the for general purpose electric motors (subtype I), DOE reduced the standard level to align with regulations in 10 CFR 431.25. See section VI for further discussion.
Table I.2—Standard Levels for Capacitor-Start Induction-Run and Capacitor-Start Capacitor-Run Small Electric Motors
Motor output power
Six poles
Four poles
Two poles
0.25 Hp/0.18 kW
62.2
68.5
66.6
0.33 Hp/0.25 kW
66.6
72.4
70.5
0.5 Hp/0.37 kW
76.2
76.2
72.4
0.75 Hp/0.55 kW
80.2
81.8
76.2
1 Hp/0.75 kW
81.1
82.6
80.4
1.5 Hp/1.1 kW
N/A
83.8
81.5
2 Hp/1.5 kW
N/A
84.5
82.9
3 Hp/2.2 kW
N/A
N/A
84.1
* Standard levels are expressed in terms of full-load efficiency.
** These efficiencies correspond to a modified Trial Standard Level 7 for capacitor-start motors. DOE reduced efficiency standards for capacitor-start induction run motors such that they harmonize with adopted capacitor-start capacitor-run motor efficiency standards. See section VI for further discussion.
B. Benefits and Burdens to Customers of Small Electric Motors
Table I.3 presents the implications of today's standards for consumers of small electric motors. The economic impacts of the standards on consumers as measured by the average life-cycle cost (LCC) savings are positive, even though the standards may increase some initial costs. For example, a typical polyphase motor has an average installed price of $517 and average lifetime operating costs (discounted) of $751. To meet the amended standards, DOE estimates that the average installed price of such equipment will increase by $72, which will be more than offset by savings of $100 in average lifetime operating costs (discounted).
Table I.3—Implications of Standards for Commercial Consumers
Equipment class
Energy conservation standard
%
Average installed price*
$
Average installed price increase
%
Average life-cycle cost
savings
$
Median payback period
years
Polyphase, 1-horsepower, 4-pole
83.5
589
72
28
7.8
Capacitor-start induction-run,
1/2
-horsepower, 4-pole
76.2
996
502
−369
12.4
Capacitor-start capacitor-run,
3/4
-horsepower, 4-pole
81.8
599
51
24
5.9
* For a baseline model.
C. Impact on Manufacturers
Using a real corporate discount rate of 9.7 percent, which DOE calculated by examining the financial statements of motor manufacturers, DOE estimates the industry net present value (INPV) of the small electric motor manufacturing industry to be $70 million for polyphase small electric motors and $279 million for capacitor-start, or single-phase motors (both figures in 2009$). DOE expects the impact of the standards on the INPV of manufacturers of small electric motors to range from a increase of 4.8 percent to a loss of 7.8 percent (an increase of $3.4 million to a loss of $5.4 million) for polyphase motors and an increase of 6.6 percent to a loss of 12.2 percent (an increase of $32.2 million to a loss of $42.2 million) for single-phase motors. Based on DOE's interviews with the major manufacturers of small electric motors, DOE expects minimal plant closings or loss of employment as a result of the standards.
D. National Benefits
The standards will provide significant benefits to the Nation. DOE estimates the standards will save approximately 2.2 quads (quadrillion (10
15
) British thermal units (BTU)) of energy over 30 years (2015-2045). This is equivalent to about 2.2% of total annual U.S. energy consumption.
By 2045, DOE expects the energy savings from the standards to eliminate the need for approximately eight new 250-megawatt (MW) power plants. These energy savings will result in cumulative greenhouse gas emission reductions of approximately 112 million tons (Mt) of carbon dioxide (CO
2
), or an amount equal to that produced by approximately 25 million new cars in a year. Additionally, the standards will help alleviate air pollution by resulting in approximately 81 thousand tons (kt) of nitrogen oxides (NO
X
) emission reductions and approximately 0.49 ton of cumulative mercury (Hg) emission reductions from 2015 through 2045. The estimated net present monetary value of these emissions reductions is between $385 and $6,081 million for CO
2
, (expressed in 2009$). The estimated net present monetary values of these emissions reductions are between $13.2 and $63.4 million for NO
X
(expressed in 2009$) and $0.12 and $5.14 million for Hg (expressed in 2009$) at a 7-percent discount rate (discounted to 2010). At a 3 percent discount rate, the estimated net present values of these emissions reductions are between $17.1 and $175.5 million (2009$) for NO
X
and $0.22 and $9.66 million (2009$) for Hg.
The national NPV of the standards is $5.3 billion using a seven-percent discount rate and $12.5 billion using a three-percent discount rate, cumulative from 2015 to 2045 in 2009$. This is the estimated total value of future savings minus the estimated increased equipment costs, discounted to the year 2009.
The benefits and costs of today's rule can also be expressed in terms of annualized (2009$) values from 2015-2045. Estimates of annualized values are shown in Table I.4. The annualized monetary values are the sum of the annualized national economic value of operating savings benefits (energy, maintenance and repair), expressed in 2009$, plus the monetary value of the benefits of CO
2
emission reductions, otherwise known as the Social Cost of Carbon (SCC), calculated using the average value derived using a 3% discount rate (equivalent to $21.40 per metric ton of CO
2
emitted in 2010, in 2007$). This value is a central value from a recent interagency process. The monetary benefits of cumulative emissions reductions are reported in 2009$ so that they can be compared with the other costs and benefits in the same dollar units. The derivation of this value is discussed in section IV.M. Although comparing the value of operating savings to the value of CO
2
reductions provides a valuable perspective, please note the following: (1) The national operating savings are domestic U.S. consumer monetary savings found in market transactions while the value of CO
2
reductions is based on a global value. Also, note that the central value is only one of four SCC developed by the interagency workgroup. Other marginal SCC values for 2010 are $4.70, $35.10, and $64.90 per metric ton (2007$ for emissions in 2010), which reflect different discount rates and, for the highest value, the possibility of higher-than-expected impacts further out in the tails of the SCC distribution. (2) The assessments of operating savings and CO
2
savings are performed with different computer models, leading to different time frames for analysis. The national operating cost savings is measured for the lifetime of small electric motors shipped in the 31-year period 2015-2045. The value of CO
2
, on the other hand, reflects the present value of all future climate related impacts due to emitting a ton of carbon dioxide in that year, out to 2300.
Using a 7-percent discount rate for the annualized cost analysis, the combined cost of the standards proposed in today's proposed rule for small electric motors is $263.9 million per year in increased equipment and installation costs, while the annualized benefits are $855.1 million per year in reduced equipment operating costs, $115.6 million in CO
2
reductions, $3.89 million in reduced NO
X
emissions, and $0.30 million in reduced Hg emissions, for a net benefit of $711.0 million per year. Using a 3-percent discount rate, the cost of the standards proposed in today's rule is $263.7 million per year in increased equipment and installation costs, while the benefits of today's standards are $989.5 million per year in reduced operating costs, $115.6 million in CO
2
reductions, $5.58 million in reduced NO
X
emissions, and $0.29 million in reduced Hg emissions, for a net benefit of $847.3 million per year.
Table I.4—Annualized Benefits and Costs for Small Electric Motors
Category
Primary estimate (AEO reference case)
Low estimate (low energy price case)
High estimate (high energy price case)
Units
Year dollars
Disc. rate
Period
covered
Benefits
Energy Annualized Monetized (millions$/year)
855.1
989.5
831.8
964.8
870.3
1000.5
2009
2009
7%
3%
31
31
Annualized Quantified
2.29 CO
2
(Mt)
2.29 CO
2
(Mt)
2.29 CO
2
(Mt)
NA
7%
31
1.55 NO
X
(kt)
1.55 NO
X
(kt)
1.55 NO
X
(kt)
NA
7%
31
0.017 Hg (t)
0.017 Hg (t)
0.017 Hg (t)
NA
7%
31
3.13 CO
2
(Mt)
3.13 CO
2
(Mt)
3.13 CO
2
(Mt)
NA
3%
31
2.22 NO
X
(kt)
2.22 NO
X
(kt)
2.22 NO
X
(kt)
NA
3%
31
0.017 Hg (t)
0.017 Hg (t)
0.017 Hg (t)
NA
3%
31
CO
2
Monetized Value (at $4.7/Metric Ton, millions$/year)*
31.5
31.5
31.5
2009
5%
31
CO
2
Monetized Value (at $21.4/Metric Ton, millions$/year)*
115.6
115.6
115.6
2009
3%
31
CO
2
Monetized Value (at $35.1/Metric Ton, millions$/year)*
179.2
179.2
179.2
2009
2.5%
31
CO
2
Monetized Value (at $64.9/Metric Ton, millions$/year)*
352.5
352.5
352.5
2009
3%
31
NO
X
Monetized Value (at $2,437/Metric Ton, millions$/year)
3.89
5.58
3.89
5.58
3.89
5.58
2009
2009
7%
3%
31
31
Hg Monetized Value (at $17 million/Metric Ton, millions$/year)
0.3
0.29
0.3
0.29
0.3
0.29
2009
2009
7%
3%
31
31
Total Monetary Benefits (millions$/year)**
890.8-1211.8
974.9
867.5-1188.5
951.6
906.0-1227.0
990.1
2009
2009
7% Range
7%
31
31
1111.0
1086.3
1121.9
2009
3%
31
1026.9-1347.9
1002.2-1323.2
1037.8-1358.8
2009
3% Range
31
Costs
Annualized Monetized (millions$/year)
263.9
263.9
263.9
2009
7%
31
263.7
263.7
263.7
2009
3%
31
Net Benefits/Costs
Annualized Monetized, including CO
2
Benefits (million$/year)**
626.9-947.9
711.0
603.6-924.6
687.7
642.1-963.1
726.2
2009
2009
7% Range
7%
31
31
847.3
822.6
858.3
2009
3%
31
763.2-1084.3
738.5-1059.6
774.2-1095.2
2009
3% Range
31
* These values represent global values (in 2007$) of the social cost of CO
2
emissions in 2010 under several scenarios. The values of $4.7, $21.4, and $35.1 per ton are the averages of SCC distributions calculated using 5%, 3%, and 2.5% discount rates, respectively. The value of $64.9 per ton represents the 95th percentile of the SCC distribution calculated using a 3% discount rate. See section IV.M for details.
** Total Monetary Benefits for both the 3% and 7% cases utilize the central estimate of social cost of CO
2
emissions calculated at a 3% discount rate (averaged across three IAMs), which is equal to $21.4/ton in 2010 (in 2007$). The rows labeled as “7% Range” and “3% Range” calculate consumer, Hg, and NO
X
cases with the labeled discount rate but add these values to the full range of CO
2
values with the $4.7/ton value at the low end, and the $64.9/ton value at the high end.
E. Conclusion
DOE has concluded that the benefits (energy savings, consumer LCC savings, national NPV increases, and emissions reductions) to the Nation of today's standards for small electric motors outweigh their costs (loss of manufacturer INPV and consumer LCC increases for some users of small electric motors). DOE has also concluded that these standards are technologically feasible and economically justified, and will result in significant energy savings. Small electric motors that are commercially available or working prototypes use or have used the technologies needed to meet the new standard levels.
II. Introduction
A. Authority
Title III of EPCA sets forth a variety of provisions designed to improve energy efficiency. Part A of Title III (42 U.S.C. 6291-6309) provides for the Energy Conservation Program for Consumer Products Other than Automobiles. Part A-1 of Title III (42 U.S.C. 6311-6317) establishes a similar program for “Certain Industrial Equipment,” which includes small electric motors, the subject of this rulemaking.
1
DOE publishes today's final rule pursuant to Part A-1 of Title III, which provides for test procedures, labeling, and energy conservation standards for small electric motors and certain other equipment, and authorizes DOE to require information and reports from manufacturers. The test procedures DOE recently adopted for small electric motors, 74 FR 32059 (July 7, 2009), appear at Title 10, Code of Federal Regulations (CFR), sections 431.443, 431.444, and 431.445.
1
These two parts were titled Parts B and C in EPCA, but were codified as Parts A and A-1 in the United States Code for editorial reasons.
The Act defines “small electric motor” as follows:
[A] NEMA [National Electrical Manufacturers Association] general purpose alternating current single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards Publication MG1-1987.
(42 U.S.C. 6311(13)(G)) EPCA requires DOE to prescribe energy conservation standards for those small electric motors for which DOE: (1) Has determined that standards would be technologically feasible and economically justified and would result in significant energy savings, and (2) has prescribed test procedures. (42 U.S.C. 6317(b)) However, pursuant to section 346(b)(3) of EPCA (42 U.S.C. 6317(b)(3)), no standard prescribed for small electric motors shall apply to any such motor that is a component of a covered product under section 322(a) of EPCA (42 U.S.C. 6292(a)), or of covered equipment under section 340 (42 U.S.C. 6311).
Additionally, EPCA requires DOE, in establishing standards for small electric motors, to consider whether the standards themselves will result in a significant conservation of energy, are technologically feasible, and are cost effective as described in 42 U.S.C. 6295(o)(2)(B)(i). (42 U.S.C. 6316(a)) These criteria, along with requirements that any standards be economically justified, are largely incorporated into
42 U.S.C. 6295(o), which sets forth the criteria for prescribing standards for “covered products,”
i.e.,
consumer products as defined in EPCA. (42 U.S.C. 6291(1) and (2)) Under 42 U.S.C. 6316(a), portions of 42 U.S.C. 6295, including subsection (o), also apply when DOE promulgates standards for certain specified commercial and industrial equipment—“covered equipment” as defined in EPCA (42 U.S.C. 6311(1))—including small electric motors. (EPCA states that the term “equipment” shall be substituted for “product” in applying the consumer product-related provisions of EPCA to commercial and industrial equipment. (42 U.S.C. 6316(a)(3))
Therefore, as indicated above, DOE analyzed whether today's standards for small electric motors will achieve the maximum improvement in energy efficiency that is technologically feasible and economically justified. (42 U.S.C. 6295(o)(2)(A)) Additionally, DOE examined whether each of today's standards for this equipment is economically justified, after receiving comments on the proposed standards, by determining whether the benefits of the standard exceed its burdens by considering, to the greatest extent practicable, the following seven factors that are set forth in 42 U.S.C. 6295(o)(2)(B)(i):
1. The economic impact of the standard on manufacturers and consumers of the equipment subject to the standard;
2. The savings in operating costs throughout the estimated average life of the covered equipment in the type (or class) compared to any increase in the price, initial charges, or maintenance expenses for the covered equipment that are likely to result from the imposition of the standard;
3. The total projected amount of energy savings likely to result directly from the imposition of the standard;
4. Any lessening of the utility or the performance of the covered equipment likely to result from the imposition of the standard;
5. The impact of any lessening of competition, as determined in writing by the Attorney General, that is likely to result from the imposition of the standard;
6. The need for national energy conservation; and
7. Other factors the Secretary [of Energy] considers relevant.
In developing today's energy conservation standards, DOE also has applied certain other provisions of 42 U.S.C. 6295 as it is required to do. First, DOE would not prescribe a standard for small electric motors if interested persons established by a preponderance of the evidence that the standard is likely to result in the unavailability in the United States of any type (or class) of this product with performance characteristics, features, sizes, capacities, and volume that are substantially the same as those generally available in the United States. (42 U.S.C. 6295(o)(4))
Second, DOE has applied 42 U.S.C. 6295(o)(2)(B)(iii), which establishes a rebuttable presumption that a standard is economically justified if the Secretary finds that “the additional cost to the consumer of purchasing a product complying with an energy conservation standard level will be less than three times the value of the energy * * * savings during the first year that the consumer will receive as a result of the standard, as calculated under the applicable test procedure.”
Third, in setting standards for a type or class of equipment that has two or more subcategories, DOE specifies a different standard level than that which applies generally to such type or class of equipment “for any group of covered products which have the same function or intended use, if * * * products within such group—(A) consume a different kind of energy from that consumed by other covered products within such type (or class); or (B) have a capacity or other performance-related feature which other products within such type (or class) do not have and such feature justifies a higher or lower standard” than applies or will apply to the other products. (42 U.S.C. 6295(q)(1)) In determining whether a performance-related feature justifies such a different standard for a group of products, DOE considers such factors as the utility to the consumer of such a feature and other factors DOE deems appropriate. Any rule prescribing such a standard must include an explanation of the basis on which DOE establishes such higher or lower level. (42 U.S.C. 6295(q)(2))
Federal energy efficiency requirements for equipment covered under EPCA generally supersede State laws or regulations concerning energy conservation testing, labeling, and standards. (42 U.S.C. 6297(a)-(c) and 42 U.S.C. 6316(a)) DOE can, however, grant waivers of preemption for particular State laws or regulations, in accordance with the procedures and other provisions of section 327(d) of the Act. (42 U.S.C. 6297(d) and 42 U.S.C. 6316(a))
B. Background
1. Current Energy Conservation Standards
As indicated above, at present there are no national energy conservation standards for small electric motors.
2. History of Standards Rulemaking for Small Electric Motors
To determine the small electric motors for which energy conservation standards would be technologically feasible and economically justified, and would result in significant energy savings, DOE first concluded that the EPCA definition of “small electric motor” covers only those motors that meet the definition's frame-size requirements, and that are either three-phase, non-servo motors (referred to below as polyphase motors) or single-phase, capacitor-start motors, including both capacitor-start, induction run (CSIR) and capacitor-start, capacitor-run (CSCR) motors. 71 FR 38799, 38800-01 (July 10, 2006). In June 2006, DOE issued a report in which it analyzed and estimated the likely range of energy savings and economic benefits that would result from standards for these motors.
2
The report did not address motors that are a component of a covered product or equipment, consistent with 42 U.S.C. 6317. After receiving comments on the report, DOE performed further analysis to determine whether standards are warranted for small electric motors and then issued the following determination on June 27, 2006:
2
http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/small_motors_tsd.pdf.
Based on its analysis of the information now available, the Department [of Energy] has determined that energy conservation standards for certain small electric motors appear to be technologically feasible and economically justified, and are likely to result in significant energy savings. Consequently, the Department [of Energy] will initiate the development of energy efficiency test procedures and standards for certain small electric motors. 71 FR 38807.
Thereafter, in 2007, DOE initiated this rulemaking by issuing and seeking public comment on the “Energy Conservation Standards Rulemaking Framework Document for Small Electric Motors,” which described the approaches DOE anticipated using to develop energy conservation standards for small electric motors and the issues to be resolved in the rulemaking. See 72 FR 44990 (August 10, 2007). This document is also available on the aforementioned DOE Web site. On September 13, 2007, DOE held a public
meeting to present the contents of the framework document, describe the analyses DOE planned to conduct during the rulemaking, obtain public comment on these subjects, and facilitate the public's involvement in the rulemaking. Manufacturers, trade associations, electric utilities, environmental advocates, regulators, and other interested parties provided comments at this meeting, and submitted written comments, on the Framework Document. They addressed a range of issues.
On December 19, 2008, after having considered these comments, gathering additional information, and performing preliminary analyses as to standards for small electric motors, DOE announced an informal public meeting and the availability on its Web site of a preliminary technical support document (preliminary TSD). 73 FR 79723 (December 30, 2008). The preliminary TSD discussed the comments DOE had received in this rulemaking and described the actions DOE had taken, the analytical framework DOE was using, and the content and results of DOE's preliminary analyses.
Id.
at 79724-25. DOE's preliminary analyses were largely based on comments received from industry; including those focusing on what constitutes small electric motors and corresponding shipment estimates. DOE convened the public meeting to discuss, and receive comments on, these subjects, DOE's proposed product classes, potential standard levels that DOE might consider, and other issues participants believed were relevant to the rulemaking.
Id.
at 79723, 79725. DOE also invited written comments on all of these matters. The public meeting took place on January 30, 2009. Eighteen interested parties participated, and ten submitted written comments during the comment period.
On November 24, 2009, DOE published a notice of proposed rulemaking (NOPR) to establish small electric motor energy conservation standards. 74 FR 61410. Shortly after, DOE also published on its Web site the complete technical support document (TSD) for the proposed rule, which incorporated the completed analyses DOE conducted and technical documentation for each analysis. These analyses were developed using, in part, NEMA-supplied data. The TSD included the LCC spreadsheet, the national impact analysis spreadsheet, and the manufacturer impact analysis (MIA) spreadsheet—all of which are available at
http://www.eere.energy.gov/buildings/appliance_standards/commercial/small_electric_motors.html.
The energy efficiency standards DOE proposed in the NOPR were as follows:
Table II.1—Proposed Standard Levels for Polyphase Small Electric Motors
Motor output power
Six poles
Four poles
Two poles
0.25 Hp/0.18 kW
77.4
72.7
69.8
0.33 Hp/0.25 kW
79.1
75.6
73.7
0.5 Hp/0.37 kW
81.1
80.1
76.0
0.75 Hp/0.55 kW
84.0
83.5
81.6
1 Hp/0.75 kW
84.2
85.2
83.6
1.5 Hp/1.1 kW
85.2
87.1
86.6
2 Hp/1.5 kW
89.2
88.0
88.2
≥ 3 Hp/2.2 kW
90.8
90.0
90.5
* Standard levels are expressed in terms of full-load efficiency.
** These efficiencies corresponded to NOPR Trial Standard Level 5 for polyphase motors.
Table II.2—Proposed Standard Levels for Capacitor-Start Induction-Run Small Electric Motors
Motor output power
Six poles
Four poles
Two poles
0.25 Hp/0.18 kW
65.4
69.8
71.4
0.33 Hp/0.25 kW
70.7
72.8
74.2
0.5 Hp/0.37 kW
77.0
77.0
76.3
0.75 Hp/0.55 kW
81.0
80.9
78.1
1 Hp/0.75 kW
84.1
82.8
80.0
1.5 Hp/1.1 kW
87.7
85.5
82.2
2 Hp/1.5 kW
89.8
86.5
85.0
≥ 3 Hp/2.2 kW
92.2
88.9
85.6
* Standard levels are expressed in terms of full-load efficiency.
** These efficiencies corresponded to NOPR Trial Standard Level 7 for capacitor-start motors.
Table II.3—Proposed Standard Levels for Capacitor-Start Capacitor-Run Small Electric Motors
Motor output power
Six poles
Four poles
Two poles
0.25 Hp/0.18 kW
63.9
68.3
70.0
0.33 Hp/0.25 kW
69.2
71.6
72.9
0.5 Hp/0.37 kW
75.8
76.0
75.1
0.75 Hp/0.55 kW
79.9
80.3
77.0
1 Hp/0.75 kW
83.2
82.0
79.0
1.5 Hp/1.1 kW
87.0
84.9
81.4
2 Hp/1.5 kW
89.1
86.1
84.2
≥ 3 Hp/2.2 kW
91.7
88.5
84.9
* Standard levels are expressed in terms of full-load efficiency.
** These efficiencies corresponded to NOPR Trial Standard Level 7 for capacitor-start motors.
In the NOPR, DOE also identified issues on which it was particularly interested in receiving the comments and views of interested parties. DOE requested comment on the proposed energy efficiency levels for polyphase and single-phase motors, product classes, covered insulation class systems, its selection of baseline models, markups used in the engineering analysis, design option and limitations used in the engineering analysis, the approach to scaling the results of the engineering analysis, the proposed definition of nominal efficiency, the manufacturer impact analysis scenarios, capital investment costs used, market interaction between CSIR and CSCR motors, market response to standards, behavior of customers with space constraints, the combined effect of certain market assumptions, the appropriateness of other discount rates besides seven and three percent to discount future emissions, and the anticipated environmental impacts. The NOPR also included additional background information on the history of this rulemaking. 74 FR 61416-17.
DOE held a public meeting in Washington, DC on December 17, 2009, to hear oral comments on, and solicit information relevant to, the proposed rule. DOE has also received written comments and information in response to the NOPR.
III. General Discussion
A. Test Procedures
On July 7, 2009, DOE published a final rule that incorporated by reference Institute of Electrical and Electronics Engineers, Inc. (IEEE) Standard 112-2004 (Test Method A and Test Method B), IEEE Standard 114-2001, and Canadian Standards Association Standard C747-94 as the DOE test procedures to measure energy efficiency small electric motors. 74 FR 32059.
In addition to incorporating by reference the above industry standard test procedures, the small electric motors test procedure final rule also codified the statutory definition for the term “small electric motor;” clarified the definition of the term “basic model”; and the relationship of the term to certain product classes and compliance certification reporting requirements; and codified the ability of manufacturers to use an alternative efficiency determination method (AEDM) to reduce testing burden when certifying their equipment as compliant but maintaining efficiency measurement accuracy and ensuring compliance with potential future energy conservation standards. The test procedure notice also discussed matters of laboratory accreditation, compliance certification, and enforcement of energy conservation standards for small electric motors.
DOE notes that complete certification and enforcement provisions for small electric motors have not yet been developed. DOE intends to propose such provisions in a separate test procedure supplementary NOPR, at which time DOE will invite comments on how small electric motor efficiency standards can be effectively enforced. Section V.B of this final rule summarizes comments received in response to the NOPR that will be further addressed in the test procedure supplemental NOPR.
B. Technological Feasibility
1. General
As stated above, any standards that DOE establishes for small electric motors must be technologically feasible. (42 U.S.C. 6295(o)(2)(A); 42 U.S.C. 6316(a)) DOE considers a design option to be technologically feasible if it is in use by the respective industry or if research has progressed to the development of a working prototype. “Technologies incorporated in commercially available equipment or in working prototypes will be considered technologically feasible.” 10 CFR part 430, subpart C, appendix A, section 4(a)(4)(i). This final rule considers the same design options as those evaluated in the NOPR. (See chapter 5 of the TSD.) All the evaluated technologies have been used (or are being used) in commercially available products or working prototypes. Therefore, DOE has determined that all of the efficiency levels evaluated in this notice are technologically feasible.
2. Maximum Technologically Feasible Levels
As required by EPCA, (42 U.S.C. 6295(p)(1) and 42 U.S.C. 6316(a)), in developing the NOPR, DOE identified the efficiency levels that would achieve the maximum improvements in energy efficiency that are technologically feasible (max-tech levels) for small electric motors. 74 FR 61418. Table III.1 lists the max-tech levels that DOE determined for this rulemaking. DOE identified these levels as part of the engineering analysis (chapter 5 of the TSD), using the most efficient design parameters that lead to the highest full-load efficiencies for small electric motors.
Table III.1—Max-Tech Efficiency Levels for Representative Product Classes *
Motor category
Poles
Horsepower
Efficiency %
Polyphase
4
1
87.7
CSIR
4
0.5
77.6
CSCR
4
0.75
87.5
* These max-tech efficiency levels are only for the representative product classes described in section IV.C.2. Max-tech efficiency levels for the remaining product classes are determined using the scaling methodology outlined in section IV.C.5.
DOE developed maximum technologically feasible efficiencies by creating motor designs for each product class analyzed, which use all the viable design options that DOE considered. The efficiency levels shown in Table III.1 correspond to designs that use a maximum increase in stack length, a copper rotor design, a premium electrical steel (Hiperco 50), a maximum slot-fill percentage (65-percent), a change in run-capacitor rating (CSCR motors only), and an optimized end ring design. All of the design options used to create these max-tech motors remain in the analysis and are options that DOE considers technologically feasible.
C. Energy Savings
DOE forecasted energy savings in its national energy savings (NES) analysis, through the use of an NES spreadsheet tool, as discussed in the NOPR. 74 FR 61418, 61440-42, 61470-72.
One of the criteria that govern DOE's adoption of standards for small electric motors is that the standard must result in “significant” energy savings. (42 U.S.C. 6317(b)) While the term “significant” is not defined by EPCA, a D.C. Circuit indicated that Congress intended “significant” energy savings to be savings that were not “genuinely
trivial.”
Natural Resources Defense Council
v.
Herrington,
768 F.2d 1355, 1373 (D.C. Cir. 1985) The energy savings for the standard levels DOE is adopting today are non-trivial, and therefore DOE considers them “significant” as required by 42 U.S.C. 6317.
D. Economic Justification
1. Specific Criteria
The following section discusses how DOE has addressed each of the seven factors that it uses to determine if energy conservation standards are economically justified.
a. Economic Impact on Motor Customers and Manufacturers
DOE considered the economic impact of today's new standards on purchasers and manufacturers of small electric motors. For purchasers of small electric motors, DOE measured the economic impact as the change in installed cost and life-cycle operating costs,
i.e.,
the LCC. (See section IV.F of this preamble, and chapter 12 of the TSD.) DOE investigated the impacts on manufacturers through the manufacturer impact analysis (MIA). (See sections IV.I and VI.C.2 of this preamble and chapter 13 of the TSD.) The economic impact on purchasers and manufacturers is discussed in detail in the NOPR. 74 FR 61418-19, 61436-40, 61442-46, and 61454-70.
b. Life-Cycle Costs
DOE considered life-cycle costs of small electric motors, as discussed in the NOPR. 74 FR 61436-40, 61442, 61454-64. In considering these costs, DOE calculated the sum of the purchase price and the operating expense—discounted over the lifetime of the equipment—to estimate the range in LCC savings that small motors purchasers would expect to achieve due to the standards.
c. Energy Savings
Although significant conservation of energy is a separate statutory requirement for imposing an energy conservation standard, EPCA also requires DOE, in determining the economic justification of a standard, to consider the total projected energy savings that are expected to result directly from the standard. (42 U.S.C. 6295(o)(2)(B)(i)(III) and 42 U.S.C. 6316(a)) As in the NOPR (74 FR 61440-42, 61470-72), for today's final rule, DOE used the NES spreadsheet results in its consideration of total projected energy savings that are directly attributable to the standard levels DOE considered.
d. Lessening of Utility or Performance of Equipment
In selecting today's standard levels, DOE avoided selection of standards that lessen the utility or performance of the equipment under consideration in this rulemaking. (See 42 U.S.C. 6295(o)(2)(B)(i)(IV) and 42 U.S.C. 6316(a)) 74 FR 61419, 61476. The efficiency levels DOE considered maintain both motor performance and power factor in order to preserve consumer utility. DOE considered end-user size constraints by developing designs with size increase restrictions (limited to a 20-percent increase in stack length), as well as designs with less stringent constraints (100-percent increase in stack length). The designs adhering to the 20-percent increase in stack length maintain all aspects of consumer utility and were created for all efficiency levels, but these designs may become very expensive at higher efficiency levels when compared with DOE's other designs.
e. Impact of Any Lessening of Competition
DOE considered any lessening of competition that is likely to result from standards. As discussed in the NOPR, 74 FR 61419, 61476, and as required under EPCA, DOE requested that the Attorney General transmit to the Secretary a written determination of the impact, if any, of any lessening of competition likely to result from the standards proposed in the NOPR, together with an analysis of the nature and extent of such impact. (42 U.S.C. 6295(o)(2)(B)(i)(V) and (B)(ii) and 42 U.S.C. 6316(a))
To assist the Attorney General in making such a determination, DOE provided the Department of Justice (DOJ) with copies of the November 24, 2009 proposed rule and the NOPR TSD for review. The Attorney General's response is discussed in IV.F.7 below, and is reprinted at the end of this rule. DOJ concluded that TSL 5 for polyphase small electric motors and TSL 7 for single-phase small electric motors are likely to affect the replacement market for certain applications. DOJ requested that DOE consider this potential impact and, as warranted, allow exemptions from the proposed standard levels the manufacture and marketing of certain replacement small electric motors.
f. Need of the Nation To Conserve Energy
In considering standards for small electric motors, the Secretary must consider the need of the Nation to conserve energy. (42 U.S.C. 6295(o)(2)(B)(i)(VI) and 42 U.S.C. 6316(a)) The Secretary recognizes that energy conservation benefits the Nation in several important ways. The non-monetary benefits of the standard are likely to be reflected in improvements to the security and reliability of the Nation's energy system. Today's standard will also result in environmental benefits. As discussed in the NOPR, 74 FR 61419, 61447-61453, 61476-61484, and in section VI.C.6 of this final rule, DOE considered these factors in adopting today's standards.
g. Other Factors
The Secretary of Energy, in determining whether a standard is economically justified, considers any other factors that the Secretary of Energy deems relevant. (42 U.S.C. 6295(o)(2)(B)(i)(VII) and 42 U.S.C. 6316(a)) In adopting today's standards, the Secretary considered the following: (1) Harmonization of standards for small electric motors with existing standards under EPCA for medium-sized polyphase general purpose motors; (2) the impact, on consumers who need to use CSIR motors, and on the prices for such motors at potential standard levels; and (3) the potential for standards to reduce reactive power demand and thereby lower costs for supplying electricity.
3
74 FR 61419-20, 61484. These issues are addressed in section VI.C.7 below.
3
In an alternating current power system, the reactive power is the root mean square (RMS) voltage multiplied by the RMS current, multiplied by the sine of the phase difference between the voltage and the current. Reactive power occurs when the inductance or capacitance of the load shifts the phase of the voltage relative to the phase of the current. While reactive power does not consume energy, it can increase losses and costs for the electricity distribution system. Motors tend to create reactive power because the windings in the motor coils have high inductance.
2. Rebuttable Presumption
Section 325(o)(2)(B)(iii) of EPCA states that there is a rebuttable presumption that an energy conservation standard is economically justified if the increased installed cost for a product that meets the standard is less than three times the value of the first-year energy savings resulting from the standard, as calculated under the applicable DOE test procedure. (42 U.S.C. 6295(o)(2)(B)(iii) and 42 U.S.C. 6316(a)) DOE's LCC and payback period (PBP) analyses generate values that calculate the PBP of potential energy conservation standards. The calculation includes, but is not limited to, the three-year PBP contemplated under the rebuttable presumption test just described. However, DOE routinely
conducts a full economic analysis that considers the full range of impacts, including those to the customer, manufacturer, Nation, and environment, as required under 42 U.S.C. 6295(o)(2)(B)(i) and 42 U.S.C. 6316(a). The results of this analysis serve as the basis for DOE to evaluate definitively the economic justification for a potential standard level (thereby supporting or rebutting any presumption of economic justification).
IV. Methodology and Discussion of Comments on Methodology
DOE used several analytical tools that it developed previously and adapted for use in this rulemaking. One is a spreadsheet that calculates LCC and PBP. Another tool calculates national energy savings and national NPV that would result from the adoption of energy conservation standards. DOE also used the Government Regulatory Impact Model (GRIM), along with other data obtained from interviews with manufacturers, in its MIA to determine the impacts of standards on manufacturers. Finally, DOE developed an approach using the National Energy Modeling System (NEMS) to estimate impacts of standards for small electric motors on electric utilities and the environment. The NOPR discusses each of these analytical tools in detail, 74 FR 61420, 61436-53, as does the TSD.
As a basis for this final rule, DOE has continued to use the spreadsheets and approaches explained in the NOPR. DOE used the same general methodology as applied in the NOPR, but revised some of the assumptions and inputs for the final rule in response to public comments. DOE also added new analysis based on the comments it received from interested parties. The following paragraphs address these revisions.
A. Market and Technology Assessment
When beginning an energy conservation standards rulemaking, DOE develops information that provides an overall picture of the market for the equipment concerned, including the purpose of the equipment, the industry structure, and market characteristics. This activity includes both quantitative and qualitative assessments based primarily on publicly available information. The subjects addressed in the market and technology assessment for this rulemaking include scope of coverage, product classes, manufacturers, quantities, and types of equipment sold and offered for sale; retail market trends; and regulatory and non-regulatory programs. See chapter 3 of the TSD for further discussion of the market and technology assessment.
1. Definition of Small Electric Motor
EPCA defines a small electric motor as “a NEMA general purpose alternating current single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards Publication MG1-1987.” 42 U.S.C. 6311(13)(G). NEMA Standards Publication MG1-1987 is an industry guidance document that addresses, among other things, various aspects related to small and medium electric motors. As denoted in the title, this version of MG1 was prepared in 1987, more than 20 years before the date of today's final rule. NEMA has since published updated versions of this document, the latest of which was released in 2006. Of particular significance is the difference in what was considered in 1987 a general purpose, alternating current motor (only open construction motors) compared to what NEMA currently considers a general purpose alternating current motor (both open and enclosed construction motors).
4
4
An open motor is constructed with ventilating openings that permit external cooling air to pass over and around the windings of the motor. An enclosed motor is constructed to prevent the free exchange of air between the inside and outside of the housing.
DOE explained its view in the NOPR as to how it currently reads 42 U.S.C. 6311(13)(G). 74 FR 61421. DOE indicated that the statute refers to MG1-1987 for purposes of ascertaining what constitutes a small electric motor. The agency explained and articulated certain assumptions in the NOPR regarding the scope of categories of motors, frame sizes, performance characteristics, insulation systems, and motor enclosures that it examined within the proposed scope of this rulemaking.
DOE received several comments criticizing the scope of DOE's coverage in its analyses. Manufacturers indicated that DOE's scope was too broad because, in their view, many of the motors DOE examined in ascertaining the energy savings potential for small electric motors, were not small electric motors under MG1-1987. For example, Emerson commented that in order for standards to be enforceable, DOE should adhere strictly to MG1-1987 in defining scope. (Emerson, No. 28 at p. 2) NEMA made similar comments echoing the same concern and argued that DOE's analysis should have been limited to the performance characteristics contained in MG1-1987. (See,
e.g.,
NEMA, No. 8 at pp. 2-5)
In contrast, Earthjustice and UL both commented that DOE was unnecessarily constraining itself by adhering to NEMA MG1-1987. See Earthjustice, Public Meeting Transcript, No. 20.4 at pp. 49-50; UL, Public Meeting Transcript, No. 20.4 at pp. 89-90. UL asserted that DOE's scope would create a negligible impact on the market, which has been shifting from the motors covered under the NOPR to other motor types (such as electronically commutated motors). (UL, Public Meeting Transcript, No. 20.4 at p. 182, UL, No. 21 at pp. 2) Earthjustice advised DOE that it should expand the scope of the rulemaking to include any “covered equipment” that it finds are justified. (Earthjustice, No. 22 at pp. 1-3) It had also noted during the preliminary analysis public meeting, that DOE could adopt a different reading of the definition by applying the phrase MG1-1987 only to the two digit frame number series requirement. Earthjustice, Public Meeting Transcript, at 47-49 (January 30, 2009).
After careful consideration of all of the comments, DOE believes that its scope of coverage in this final rule is appropriate. As such, DOE is declining to revise its scope of coverage for this equipment within this rulemaking. While DOE is continuing to adhere to the approach proposed in its NOPR and accompanying TSD, DOE may revisit this issue in the future and re-examine its interpretation of the small electric motor definition in 42 U.S.C. 6311(13)(G). Any such re-examination would be performed within the context of the rulemaking process and offer an opportunity for public comment.
a. Motor Categories
The motor categories examined by DOE are tied in part to the terminology and performance requirements in NEMA MG1-1987. These requirements were established for (1) general-purpose alternating-current motors, (2) single-speed induction motors, and (3) the NEMA system for designating (two-digit) frame sizes. Single-speed induction motors, as delineated and described in MG1-1987, fall into five categories: split-phase, shaded-pole, capacitor-start (both CSIR and CSCR), permanent-split capacitor (PSC), and polyphase. Of these five motor categories, DOE determined for purposes of this rulemaking that only CSIR, CSCR, and polyphase motors are able to meet performance requirements in NEMA MG1 and are widely considered general purpose alternating current motors, as shown by the listings found in manufacturers' catalogs. Therefore, in the NOPR DOE proposed
to only cover those three motor categories.
Underwriters Laboratories stated that they believe DOE should cover the split-phase, shaded-pole, and PSC motor categories because they are much more common in the current market. (Underwriters Laboratories, No. 21 at p. 2) It is DOE's understanding that the motors suggested for coverage by UL do not meet the requirements for a NEMA general purpose motors and, consequently, are outside the scope of this rulemaking despite being more common. As a result, DOE continues to maintain that CSIR, CSCR, and polyphase motors are the only motor categories that are general purpose motors for purposes of this rulemaking.
b. Horsepower Ratings
In DOE's preliminary and NOPR analyses on small electric motors, DOE presented a range of horsepower ratings from
1/4
-horsepower up to 3-horsepower. The range of horsepower ratings was the same for all three motor categories covered: CSIR, CSCR, and polyphase motors as well as all three pole configurations: Two, four, and six. This range of horsepower ratings was consistent with what DOE believed to be the range of ratings where manufacturers build NEMA general purpose motors in a two-digit frame number series.
In response to the NOPR, NEMA and Baldor commented that the horsepower range for the products classes DOE proposed was incorrect. Baldor stated that horsepower ratings higher than
1/2
-horsepower for six-pole motors,
3/4
-horsepower for four-pole motors, and 1-horsepower for two-pole motors are not standard ratings for small electric motors as defined in NEMA MG1, in particular, as listed in Table 10-1 of MG1-1987. Therefore, NEMA and Baldor stated that motors with such ratings are not NEMA general purpose motors and should be excluded from DOE's scope of coverage. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 38-41; NEMA, No. 24 at pp. 1-5, 7)
DOE understands that NEMA MG1-1987 does not provide ratings for small motors of the identified higher horsepower ratings. However, DOE does not believe this precludes certain higher horsepower ratings built in a two-digit NEMA frame consistent with NEMA MG1-1987 from coverage. In addition, upon review of NEMA manufacturer product catalogs, DOE noted that two-digit frame size motors of higher horsepower ratings are commonly marketed as general purpose. DOE also observed from NEMA shipment data provided to DOE for the determination analysis that when NEMA surveyed its members and requested shipments of general purpose motors built in a two-digit frame number series, responding manufacturers provided shipments data in horsepower ratings exceeding those listed in the comments above. Although NEMA argued that these motors do not fall within this rulemaking, NEMA did not deny that these motors are considered general purpose motors. Thus, DOE believes that even though NEMA MG1-1987 does not provide standard ratings for higher horsepower small electric motors, many of these motors are considered NEMA general purpose motors that could be considered for coverage by DOE.
DOE notes that there is precedent for clarifying the scope of coverage of these motors. At industry's request during the test procedure rulemaking for small electric motors, DOE clarified the small electric motor definition to incorporate metric-equivalent motors that are built in accordance with the International Electrotechnical Commission's requirements. See Baldor, Public Meeting Transcript, No. 8 at p. 75; NEMA, No. 12 at p. 2. This expansion of the small electric motor definition, which was added to ensure that DOE provided adequate coverage over small electric motors generally, was incorporated into 10 CFR 431.442. See also 74 FR 32061-62 and 32072.
While DOE believes that many of the horsepower ratings recommended for exclusion by NEMA and Baldor could be included in the definition of small electric motors, upon examining manufacturer catalogs, DOE found that motors did not exist for some horsepower ratings/pole configuration combinations included in NOPR. Specifically, DOE found that no open construction, two-digit frame size motors have horsepower ratings greater than 3-horsepower. In addition, DOE found no small electric polyphase motors built with a 2- or 3-horsepower rating and a six-pole configuration. DOE also found that small electric single-phase motors (CSIR and CSCR) do not exist with a 1
1/2
-horsepower rating or higher for six-poles or a 3-horsepower rating for four-poles. As there is no evidence that these motors, if manufactured, would be considered general purpose motors, and because DOE lacks data on which to base energy conservation standards for these motors, DOE is not including them in the scope of this rulemaking. Today's final rule reflects this decision as no standards are being adopted in those product classes. Table IV.1 presents the horsepower ratings for which DOE believes no small electric motors are currently commercially available.
Table IV.1—Horsepower Ratings for Which No Motors Exist
Motor category
Two-pole
Four-pole
Six-pole
Polyphase
≥ 2 Hp.
Single-Phase
≥ 3 Hp
≥ 1.5 Hp.
c. Performance Requirements
NEMA defines several performance requirements, including breakdown torque, locked rotor torque, and locked rotor current that motors must meet in order to be considered general-purpose. Because DOE's assessment of the small electric motors market (through analysis of commercially-available products sold) indicates that the vast majority of motors meet the previously listed requirements, DOE believes that a motor must meet these performance characteristics as a condition for coverage.
PG&E commented that a loophole exists in the rulemaking since the current definition of a small general purpose motor is so narrow with respect to design and performance characteristics. (PG&E, Public Meeting Transcript, No. 20.4 at pp. 259-60) PG&E added that DOE's reliance on MG1-1987 provides another loophole where NEMA could update its standards such that manufacturers could still make a NEMA general purpose motor that is not covered under today's rulemaking. (PG&E, Public Meeting Transcript, No. 20.4 at pp. 260-61) NEEA/NPCC agreed with PG&E that a manufacturer could easily circumvent any standards whose coverage was based around NEMA performance requirements, by simply constructing the motor such that it slightly deviates from NEMA requirements, but still provides similar utility to the consumer. (NEEA/NPCC, No. 27, pp. 2-3) Baldor
stated that the tables of performance requirements in NEMA MG1 are designed to let customers know how motors will perform from manufacturer to manufacturer and they have been established for many years and there would be no reason to change them. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 266-67)
DOE understands the concerns expressed by PG&E, but agrees with Baldor that considering that the relevant performance requirements in NEMA MG1 have not changed substantially in over 20 years, these performance standards are unlikely to change should NEMA develop a new version of MG1. DOE believes that to do so would constitute a major change to the industry and performance characteristics that customers have been accustomed to over the years. Therefore, DOE believes that small electric motors must meet certain requirements in NEMA MG1-1987 shown in Table IV.6. For those combinations of horsepower rating and pole configuration that do not have performance requirements for two-digit frame sizes, DOE has no performance requirements. Instead, DOE will cover only those motors widely considered general purpose and marketed as such in manufacturer catalogs.
d. Motor Enclosures
In the NOPR, DOE stated that in ascertaining what constitutes a small electric motor, only the 1987 version of MG1 applies within the context of the statutory definition. Under that interpretation, DOE stated that only open construction motors were considered covered products. DOE is continuing to adhere to this approach.
As DOE's proposed scope did not extend beyond open motors as covered products, Baldor and NEMA commented that the revision to 10 CFR Part 431 proposed in the NOPR should clearly mention that the table of efficiency values for section 431.446 applies only to open motors. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 47-48, NEMA, No. 24 at p. 5) To clarify the application of the new efficiency values, DOE is modifying the efficiency standards tables in section 431.446 from today's final rule to include the words, “open motors” in the headings.
e. Frame Sizes
As for the frame sizes of motors that are covered by DOE standards for small electric motors, EPCA defines a small electric motor, in relevant part, as a motor “built in a two-digit frame number series in accordance with NEMA Standards Publication MG1-1987.” (42 U.S.C. 6311(13)(G)) MG1-1987 establishes a system for designating motor frames that consisting of a series of numbers in combination with letters that correspond to a specific size. The 1987 version of MG1 designates three two-digit frame series: 42, 48, and 56. These frame series have standard dimensions and tolerances necessary for mounting and interchangeability that are specified in sections MG1-11.31 and MG1-11.34.
DOE understands that manufacturers produce motors in other two-digit frame sizes, namely a 66 frame size. The 66 frame size is used for definite-purpose or special-purpose motors and not used in general-purpose applications and are not covered under the EPCA definition of “small electric motor.” In the NOPR, DOE stated that it was unaware of any other motors with two-digit frame sizes that are built in accordance with NEMA MG1-1987. Should such frame sizes appear on the market, DOE will consider evaluating whether to include that equipment. For the NOPR, DOE received no comments regarding this issue and as a result, is maintaining its stance on this topic for this final rule.
f. Insulation Class Systems
Because DOE's interpretation of the statutory definition of a small electric motor is largely influenced by what NEMA defines as a general-purpose alternating-current motor under MG1-1987, DOE has taken into account the criteria that comprise a general purpose motor. Among these criteria are the applicable insulation classes. NEMA MG1-1987 paragraph 1-1.05, provides that a general-purpose motor must incorporate a “Class A insulation system with a temperature rise as specified in MG 1-12.42 for small motors or Class B insulation system with a temperature rise as specified in MG 1-12.43 for medium motors.”
In NEMA MG1-1987, paragraphs 1.66 and 12.42.1 define four insulation class systems: Class A, Class B, Class F, and Class H. They are divided into classes based on the thermal endurance and each system has a different temperature rise
5
that the insulating material must be able to withstand without degradation. The temperature rise requirement for Class A systems is the lowest of the four systems defined in NEMA MG1-1987, which means that all other insulation classes meet Class A requirements. Because all insulation class systems meet the Class A requirements, DOE proposed to cover motors that incorporate any of the other insulation class systems in the NOPR. A joint comment submitted by Pacific Gas and Electric Company (PG&E), Southern California Edison (SCE), Southern California Gas Company (SCGC), and San Diego Gas and Electric Company (SDGE) supported DOE's decision to include insulation Classes B, F, and H in addition to Class A. (Joint Comment, No. 23 at p. 2) NEMA and Baldor commented that although it is prudent to cover insulation class systems other than Class A, in order for a motor to be considered covered it must adhere to the temperature rise limits required of Class A motors by NEMA MG1. For example, if a motor contains a Class B insulation system, but the temperature rise exceeds the threshold for Class A insulation systems, the commenters stated that that motor should be excluded from coverage. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 25-26; Baldor, No. 15 at p. 3-4, NEMA, No. 24 at pp. 5-7)
5
Temperature rise refers to the increase in temperature over the ambient temperature of the motor when operated at service factor load. NEMA MG1 provides maximum temperature rises (as measured on the windings of the motor) for each insulation class system.
DOE disagrees with Baldor and NEMA's assessment regarding temperature rise and in today's final rule maintains that the scope of coverage includes motors with any insulation class system Class A or higher, regardless of whether a motor meets the Class A temperature rise requirements. First, DOE notes that NEMA MG1 does not require small motors to meet the temperature rise for a Class A insulation system. Rather, it only requires that the motor incorporates an insulation system that meets Class A requirements, which DOE has determined could be Class A, B, F, or H.
Second, DOE believes that it is unreasonable to apply a more stringent temperature rise requirement on motors with higher insulation class systems. These motors often incorporate the higher insulation class systems in order to protect the motors from degradation at high temperatures. As a result, the accompanying temperature rise, which serves as a marker of how much heat a particular insulation class can withstand to prevent the motor from damage, will generally increase as a higher grade of insulation is used. Baldor's suggestion that a lower temperature rise (70 °C) must be used for each higher grade of insulation that offers protection at higher temperatures is one that DOE declines to adopt.
Furthermore, according to NEMA Standards publication MG1-1987, paragraph 10.39.1, although insulation class system designation is a required
marking on the nameplate of small electric motors, temperature rise is not. If DOE were to limit scope based on the temperature rise requirements of Class A systems, DOE would have no way of determining whether motors of insulation class systems greater than Class A meet the required temperature rise and are therefore subject to energy conservation standards. As only 2 percent of small electric motor models sold are labeled with Class A insulation systems, 98 percent of small electric models would have unknown temperature rises (relative to Class A requirements). DOE believes that including all insulation classes and temperature rises satisfies the statutory definition and avoids creating an unenforceable standard for a large number of motors that do not list temperature rise.
g. Service Factors
Some CSIR, CSCR, and polyphase motors may fail to meet the NEMA definition of general purpose alternating current motor because they do not meet NEMA service factor requirements. See,
e.g.
NEMA MG1-1987 Table 12-2. Service factor is a measure of the overload capacity at which a motor can operate without thermal damage, while operating normally within the correct voltage tolerances. The rated horsepower multiplied by the service factor determines that overload capacity. For example, a 1-horsepower motor with a 1.25 service factor can operate at 1.25 horsepower (1-horsepower × 1.25 service factor). For the NOPR, DOE concluded that motors that fail to meet service factor requirements in MG1-12.47 of MG1-1987 (now 12.51.1 of MG1-2006) are not “small electric motors” as EPCA uses that term. Receiving no comments to the contrary, DOE maintains that position in today's final rule and energy efficiency standards do not apply to them.
h. Metric Equivalents and Non-Standard Horsepower and Kilowatt Ratings
DOE's interpretation of a small electric motor is largely based on the construction and rating system in NEMA MG1-1987. (42 U.S.C. 6311(13)(G)) This system uses English units of measurement and power output ratings in horsepower. In contrast, general-purpose electric motors manufactured outside the United States and Canada are defined and described with reference to the International Electrotechnical Commission (IEC) Standard 60034-1 series, “Rotating electrical machines,” which employs terminology and criteria different from those in EPCA. The performance attributes of these IEC motors are rated pursuant to IEC Standard 60034-1 Part 1: “Rating and performance,” which uses metric units of measurement and construction standards different from MG1, and a rating system based on power output in kilowatts instead of power output in horsepower. The Institute of Electrical and Electronics Engineers (IEEE) Standard 112 recognizes this difference in the market and defines the relationship between horsepower and kilowatts. Furthermore, in 10 CFR 431.12, DOE defined “electric motor” in terms of both NEMA and IEC equivalents even though EPCA's corresponding definition and standards were articulated in terms of MG1 criteria and English units of measurement. 64 FR 54114 (October 5, 1999) The test procedure final rule adopted a definition for small electric motor that explicitly indicated that IEC equivalent motors are considered small electric motors. 10 CFR 431.442. 74 FR 32062, 72.
In the NOPR, DOE addressed how IEC metric or kilowatt-equivalent motors can perform identical functions as NEMA small electric motors and provide comparable rotational mechanical power to the same machines or equipment. Moreover, IEC metric or kilowatt-equivalent motors can generally be interchangeable with covered small electric motors. Consistent with the codified definition of “small electric motor in 10 CFR 431.442, DOE interpreted EPCA to apply the term “small electric motor” to any motor that is identical or equivalent to a motor constructed and rated in accordance with NEMA MG1, which includes IEC metric motors. DOE also proposed that motors with non-standard kilowatt and horsepower ratings would be required to meet small electric motor energy conservation standards. 74 FR 61422.
A joint comment submitted by PG&E, SCE, SCGC, and SDGE indicated support for DOE's decision to include IEC-rated motors in today's rulemaking. (Joint Comment, No. 23 at p. 2) NEMA and Baldor commented that, even though they agreed with DOE's approach in the NOPR, they believed that given the statutory definition's dependence on MG1-1987 (and the ratings contained in that standard) more justification is needed to include non-standard metric or English-rated motors in its scope of coverage. (Public Meeting Transcript, No. 20.4 at pp. 288-89; NEMA, No. 24 at pp. 24-25)
DOE appreciates these comments and in this final rule maintains its position regarding the inclusion of non-standard IEC metric and English-rated motors. Though NEMA MG1 does not provide ratings for these non-standard motors, DOE recognizes that they can perform identical functions as those NEMA motors with standard horsepower ratings. Therefore, as DOE did within the context of its codified definition of the term “small electric motor” found in 10 CFR 431.442 to include IEC metric-equivalent motors, DOE believes that non-standard horsepower and kilowatt rated motors should be considered NEMA general purpose and included in the scope of coverage of this rulemaking.
i. Summary
During the public meeting, Baldor and NEMA commented that DOE did not include the definition of NEMA general purpose motor in 10 CFR 431.442, and suggested that DOE include the definition for clarity and completeness. (Baldor, Public Meeting Transcript, No. 20.4 at p. 46; NEMA, No. 24 at p. 5) A.O. Smith also requested clarification of the term “small electric motor,” and suggested that the definition align with NEMA established guidelines. (A.O. Smith, No. 26 at p. 2)
DOE has discussed the covered motor categories, horsepower ratings, motor enclosures, frame sizes, insulation class systems, service factors, and metric equivalents. As discussed in section IV.A.1.b, because DOE has found several horsepower/pole configurations for which small electric motors are not commercially available, DOE has made slight modifications in the range of horsepower ratings for which it is adopting standards in this final rule. The motors covered by today's rule include polyphase motors from
1/4
- to 3-horsepower for motors equipped with two poles,
1/4
- to 3-horsepower for motors with four poles, and
1/4
- to
1/2
-horsepower for motors with six pole motors as long as they are built in a two-digit frame number series and with an open construction; the CSIR and CSCR motors covered by today's rule include motors from
1/4
- to 3-horsepower motors equipped with two poles,
1/4
- to 2-horsepower for motors with four poles, and
1/4
- to 1-horesepower for motors with six poles as long as they are built in a two-digit frame number series and with an open construction. A motor will not be excluded because of its insulation class system or its temperature rise. However, it will be excluded if it fails to meet NEMA general purpose service factor requirements. Any metric-equivalent motor or motor with a non-standard horsepower or kilowatt rating that has performance characteristics and construction equivalent to those listed
above is also a covered product and must meet the energy efficiency standards of this rulemaking. Although today's final rule DOE does not codify a definition for “NEMA general purpose motor”, DOE will consider proposing a definition for this term in the electric motor test procedure supplemental NOPR.
2. Product Classes
When evaluating and establishing energy conservation standards, DOE generally divides covered equipment into classes by the type of energy used, capacity, or other performance-related features that affect efficiency. (42 U.S.C. 6295(q)) DOE routinely establishes different energy conservation standards for different product classes based on these criteria.
At the NOPR public meeting, DOE presented its rationale for creating 72 product classes. The 72 product classes were based on combinations of three different characteristics: motor category, number of poles, and horsepower. As these motor characteristics change, so does the utility and efficiency of the small electric motor.
The motor category divides the small electric motors market into three major groups: CSIR, CSCR, and polyphase. For each motor category, DOE divided the product classes by all combinations of eight different horsepower ratings (
i.e.,
1/4
to ≥ 3) and three different pole configurations (
i.e.,
2, 4, and 6). A change in motor category can constitute a change in the type of power used, three-phase power for polyphase motors versus single-phase power for capacitor-start motors. Alternatively, it might be a change in consumer utility that affects efficiency. The addition of a run-capacitor on a CSCR motors can make the motor more efficient as well as constitute dimensional changes as the run-capacitor is usually mounted externally on the housing. Horsepower rating is directly related to a motor's capacity, and its pole configuration is directly related to the theoretical maximum speed at which a motor can operate. For the NOPR, DOE received no comments contrary to disaggregating product classes with these characteristics, but did receive other comments regarding product classes.
Consistent with their comments on scope (discussed in section IV.A.1), NEMA and Baldor stated that certain combinations of horsepower and speed (or pole-configuration) ratings should be excluded from DOE's product classes because, in their view, they are not small electric motors within the context of MG1-1987. Specifically, they stated that motors with horsepower ratings greater than 1-horsepower for two-pole motors, greater than
3/4
-horsepower for four-pole motors, and greater than
1/2
-horsepower for six-pole motors do not meet the statutory definition. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 39-41; NEMA, No. 24 at pp. 3-4) As discussed in section IV.A.1, DOE examined the statutory definition of small electric motor and disagrees that the aforementioned horsepower and speed ratings are not covered under this rulemaking. Therefore, in this final rule DOE is maintaining coverage of combinations of horsepower and pole configurations higher than those recommended by NEMA and Baldor. However, as discussed in section IV.A.1.b, DOE is not adopting standards for motors which are not currently commercially available. Accordingly, DOE has removed these proposed product classes in the final rule, resulting in 62 total product classes.
NEMA and Baldor also commented that DOE should include frame size among the characteristics that define a product class. They stated that smaller frame size motors will not be able to achieve as high an energy efficiency rating as the larger frame sized motors, thus warranting separate product classes. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 43-44, NEMA, No. 24 at pp. 4-5, 23)
DOE acknowledges that motors built with smaller dimensions, namely core diameters, may not be able to achieve the same efficiency as a motor with larger dimensions. The smaller diameter limits the amount of active material that is used to reduce motor losses and therefore limits the maximum efficiency rating possible as well. However, frame size, which relates to the frame housing and not the core diameter, is a measurement of height from the bottom of the mounting feet to the center of the shaft of the motor. Frame size does not always correlate to the core diameter of the motor and amount active material. For example, DOE found that some motors with larger frame sizes have core diameters equivalent to those motors built in smaller frame sizes, which means that these motors have an efficiency potential equivalent to that of a motor in a smaller frame size. Consequently, frame size alone does not necessarily change the efficiency of a small electric motor.
Additionally, NEMA MG1 does not differentiate breakdown torque, locked-rotor torque, and locked-rotor current requirements for small general-purpose motors by frame size. DOE believes that if performance requirements other than efficiency for small motors are not different for different frame sizes, there is no need or precedent for DOE to differentiate efficiency standards for small electric motors based on frame size.
However, as stated earlier, DOE recognizes that core diameter affects efficiency. If DOE were to set a standard based on an analysis of a motor of larger core diameter, it could potentially be eliminating from market smaller core diameter motors. However, because core diameter is not a standardized dimension across all small electric motors, DOE has chosen to address this issue in the engineering analysis. As discussed in section IV.C DOE based its representative unit and scaling analyses on what it perceived as the greatest dimensionally constrained motors on the market for each product class. By doing this, DOE ensures that all existing consumer utility in the marketplace of smaller core diameter motors is maintained with energy conservation standards.
Chapter 3 of the TSD accompanying today's notice provides additional detail on the product classes defined for the standards proposed in this final rule, and Table IV.2 through Table IV.4 below enumerate these product classes. For the final rule, DOE considers 62 product classes.
Table IV.2—Product Classes for Polyphase Motors With an Open Construction
Motor horsepower/standard kilowatt equivalent
Six poles
Four poles
Two poles
1/4
hp/0.18 kW
PC #1
PC #2
PC #3.
1/3
hp/0.25 kW
PC #4
PC #5
PC #6.
1/2
hp/0.37 kW
PC #7
PC #8
PC #9.
3/4
hp/0.55 kW
PC #10
PC #11
PC #12.
1 hp/0.75 kW
PC #13
PC #14
PC #15.
1
1/2
hp/1.1 kW
PC #16
PC #17
PC #18.
2 hp/1.5 kW
PC #19
PC #20.
3 hp/2.2 kW
PC #21
PC #22.
Table IV.3—Product Classes for Capacitor-Start Induction-Run Motors With an Open Construction
Motor horsepower/standard kilowatt equivalent
Six poles
Four poles
Two poles
1/4
hp/0.18 kW
PC #23
PC #24
PC #25.
1/3
hp/0.25 kW
PC #26
PC #27
PC #28.
1/2
hp/0.37 kW
PC #29
PC #30
PC #31.
3/4
hp/0.55 kW
PC #32
PC #33
PC #34.
1 hp/0.75 kW
PC #35
PC #36
PC #37.
1
1/2
hp/1.1 kW
PC #38
PC #39.
2 hp/1.5 kW
PC #40
PC #41.
3 hp/2.2 kW
PC #42.
Table IV.4—Product Classes for Capacitor-Start Capacitor-Run Motors With an Open Construction
Motor horsepower/standard kilowatt equivalent
Six poles
Four poles
Two poles
1/4
hp/0.18 kW
PC #43
PC #44
PC #45.
1/3
hp/0.25 kW
PC #46
PC #47
PC #48.
1/2
hp/0.37 kW
PC #49
PC #50
PC #51.
3/4
hp/0.55 kW
PC #52
PC #53
PC #54.
1 hp/0.75 kW
PC #55
PC #56
PC #57.
1
1/2
hp/1.1 kW
PC #58
PC #59.
2 hp/1.5 kW
PC #60
PC #61.
3 hp/2.2 kW
PC #62.
B. Screening Analysis
The purpose of the screening analysis is to evaluate the technology options identified as having the potential to improve the efficiency of equipment, to determine which technologies to consider further and which to screen out. DOE consulted with industry, technical experts, and other interested parties to develop a list of technologies for consideration. DOE then applied the following four screening criteria to determine which design options are suitable for further consideration in a standards rulemaking:
1.
Technological feasibility.
DOE considers technologies incorporated in commercial products or in working prototypes to be technologically feasible.
2.
Practicability to manufacture, install, and service.
If mass production and reliable installation and servicing of a technology in commercial products could be achieved on the scale necessary to serve the relevant market at the time the standard comes into effect, then DOE considers that technology practicable to manufacture, install, and service.
3.
Adverse impacts on product utility or product availability.
If DOE determines a technology would have a significant adverse impact on the utility of the product to significant subgroups of consumers, or would result in the unavailability of any covered product type with performance characteristics (including reliability), features, sizes, capacities, and volumes that are substantially the same as products generally available in the United States at the time, it will not consider this technology further.
4.
Adverse impacts on health or safety.
If DOE determines that a technology will have significant adverse impacts on health or safety, it will not consider this technology further.
See 10 CFR part 430, subpart C, appendix A, (4)(a)(4) and (5)(b).
DOE identified the following technology options that could improve the efficiency of small electric motors: Utilizing a copper die-cast rotor, reducing skew on the rotor stack (
i.e.
straightening the rotor conductor bars), increasing the cross-sectional area of rotor conductor bars, increasing the end ring size, changing the copper wire gauge used in the stator, manipulating the stator slot size, changing capacitor ratings, decreasing the air gap between the rotor and stator, improving the grades of electrical steel, using thinner steel laminations, annealing steel laminations, adding stack length, using high efficiency steel lamination materials, using plastic bonded iron powder (PBIP), installing better ball bearings and lubricant, and installing a more efficient cooling system. For a description of how each of these technology options improves small electric motor efficiency see TSD chapter 3. For the NOPR, DOE screened out two of these technology options: PBIP and decreasing the air gap below .0125 inch. DOE received no comments regarding these two technology options and therefore maintains its exclusion of these technology options in today's final rule. However, DOE did receive comments concerning the availability of premium electrical steels (such as Hiperco) and copper rotors, two design options that it did not screen out in the NOPR. Please see section IV.I for a discussion of those issues.
DOE believes that all of the efficiency levels discussed in today's notice are technologically feasible. The technologies that DOE examined have been used (or are being used) in commercially available equipment or working prototypes. These technologies all incorporate materials and components that are commercially available in today's supply markets for the motors that are the subject of this final rule.
C. Engineering Analysis
The engineering analysis develops cost-efficiency relationships to show the manufacturing costs of achieving increased energy efficiency. As discussed in the NOPR, to conduct the
engineering analysis, DOE used a combined design-option and efficiency level approach in which it employed a motor design software technical expert to develop motor designs at several efficiency levels for each analyzed product class. Based on these simulated designs and manufacturer and component supplier data, DOE calculated manufacturing costs and selling prices associated with each efficiency level. DOE decided on this approach after receiving insufficient response to its request for the manufacturer data needed to execute an efficiency-level approach for the preliminary analyses. The design-option approach allowed DOE to make its engineering analysis methodologies, assumptions, and results publicly available in the NOPR, thereby permitting all interested parties the opportunity to review and comment on this information. The design options considered in the engineering analysis include: Copper die-cast rotor, reduced skew on the rotor stack, increased cross-sectional area of rotor conductor bars, increase end-ring size, changing the gauge of copper wire in the stator, manipulating stator slot size, decreased air gap between rotor and stator to .0125 inch, improved grades of electrical steel, use thinner steel laminations, annealed steel laminations, increased stack height, modified capacitors ratings, improved ball bearings and lubricant, and more efficient cooling systems. Chapter 5 of the TSD contains a detailed description of the engineering analysis methodology and chapter 3 of the TSD contains a detailed description of how the design options listed above increase motor efficiency.
1. Product Classes Analyzed
As discussed in section IV.A.2 of this notice, DOE is establishing a total of 62 product classes for small electric motors, based on the motor category (polyphase, CSIR, or CSCR), horsepower rating, and pole configuration. DOE carefully selected certain product classes to analyze, and then scaled its analytical findings for those representative product classes to other product classes that were not directly analyzed. Further discussion of DOE's scaling methodology is presented in section IV.C.5
For the NOPR, DOE analyzed three representative product classes: (1) 1-horsepower, four-pole, polyphase motor, (2)
1/2
-horsepower, four-pole, CSIR motors, and (3)
3/4
-horsepower, four-pole, CSCR motor. By choosing these three product classes, DOE ensured that each motor category (polyphase, CSIR, and CSCR) was represented. DOE achieved this by selecting horsepower ratings for each motor category that are commonly available from most manufacturers, thus increasing the quantity of available data on which to base the analysis. Finally, DOE chose four-pole motors for each motor category, consistent with NEMA-provided shipments data (see TSD chapter 9), which indicated that these motors had the highest shipment volume in 2007. See TSD chapter 5 for additional detail on the product classes analyzed.
In response to the NOPR, Baldor and NEMA commented that the product class selected for polyphase motors was inappropriate. They asserted that according to NEMA's standard ratings in MG1-1987, a 1-horsepower, four-pole, polyphase motor would not be considered a small motor or NEMA general purpose small motor, and therefore falls out of the scope of this rulemaking. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 62-63; NEMA, No. 24 at p. 7) However, as discussed in section IV.A.1, DOE disagrees with Baldor and NEMA's interpretation of scope, and in this final rule, DOE is including small electric motors with horsepower ratings ranging from
1/4
- to 3-horsepower and pole configurations of two, four, and six poles. In consideration of this scope, DOE believes that the representative product classes selected in the NOPR engineering analysis are appropriate and is continuing to use these same representative product classes in today's final rule.
2. Baseline Models
The engineering analysis DOE conducted calculates the incremental costs for equipment with efficiency levels above the baseline in each product class analyzed. For the NOPR analysis, DOE established the baseline motor efficiency and design for the three representative product classes by purchasing what it believed to be the lowest efficiency motors on the market for each of these classes. To select these baseline motors, DOE interviewed manufacturers and used catalog data on motor efficiency and physical dimensions. DOE recognizes that motors with smaller core diameters, may be unable to achieve efficiencies as high as those with larger core diameters. In order to preserve the availability of these smaller core diameter motors, DOE selected baselines which it believed represented the most dimensionally constrained, in terms of core diameter, and least efficient motors currently available on the market.
After purchasing the three baseline small electric motors, DOE tested the motors according to the appropriate IEEE test procedures (as dictated by DOE's small electric motor test procedure discussed in section III.A). After performing the appropriate test procedures, DOE then tore down each baseline motor to obtain internal dimensions, copper wire gauges, steel grade, and any other pertinent design information. Those parameters and tests were then used as inputs into the design software, allowing DOE to model the motor and calibrate its software to the tested efficiencies. All subsequent higher-efficiency motor designs employed the design options discussed earlier to model incremental improvements in efficiency and increases in cost over the baseline.
a. Baseline Efficiencies
At the NOPR public meeting, DOE received several comments regarding the validity of the baseline motor efficiencies used in the engineering analysis. Emerson Motor Company pointed out that it is common to see a spread in efficiencies within a population of motors of a particular design. Emerson questioned if an analysis was conducted to determine if the baseline polyphase motor chosen and tested had an efficiency value that was at the high-end, low-end, or near the average compared to the population of motors of that model type. (Emerson, Public Meeting Transcript, No. 20.4 at pp. 73-75) Similarly, Baldor and NEMA noted that the baseline polyphase motor's tested efficiency (77 percent) varied significantly from the catalog efficiency (74 percent). They commented that using 77 percent as the efficiency of the baseline motor in the engineering analysis assumed that a single tested value of efficiency is equal to the true arithmetic mean of the full-load efficiencies of the population of motors. They argued that given the distribution of efficiencies commonly seen across a population of motors, due in part to factors such as manufacturing variability, this would be an inappropriate assumption. In addition, they also cited the electric motor compliance provisions (in 10 CFR 431.17) for support. These provisions state that the lowest full-load efficiency in a sample can differ from the nominal full load efficiency by as much as 15 percent due to variations in losses attributable to variability in manufacturing and testing facilities. Baldor and NEMA asserted that similar conditions should be expected for small motors. Baldor and NEMA recommended that absent any other
data, DOE should use the manufacturer-rated catalog efficiency of the polyphase motor (74 percent) as the baseline efficiency. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 120-121, 125; NEMA, No. 24 at p. 11, 13)
DOE agrees that it is possible that one tested efficiency value does not represent the average efficiency over a population of motors. Inconsistencies in motor laminations and processing during manufacturing can result in motors of a single design having a distribution of efficiencies, most commonly seen as variability in core and stray load losses. However, as manufacturers were not required to report its catalog efficiencies for these motors based on the results of the DOE test procedures, DOE does not agree with NEMA's assertion that catalog efficiencies should be used as the baseline efficiencies.
In consideration of the comments received, DOE conducted additional testing to validate the polyphase baseline efficiency. DOE tested five additional polyphase motors (for a total of six tests, exceeding the minimum five required by the DOE sampling requirements for electric motors in 10 CFR 431.17) of the same baseline model, purchased from five separate warehouses in order to ensure the maximum variability in production. DOE then used the average of the six tests as the baseline efficiency for the polyphase motor. For the single-phase baseline motors, because the tested values did not deviate significantly from the catalog efficiency values and as DOE did not receive specific comments opposing these values, DOE used the single-tested efficiency values as the baseline efficiencies.
Because DOE modified the efficiencies of the baseline designs relative to that which was calculated in the motor design software, DOE felt it necessary to evaluate whether the efficiencies of the higher efficiency designs modeled in the software would also change. As stated earlier, DOE calibrated its software model to the NOPR tested efficiencies of the baseline models, and all subsequent higher efficiency motor designs were generated as incremental efficiency gains and cost increases over this baseline design. Thus, a change in the baseline efficiency would likely affect the efficiencies of the other motor designs. Therefore, for this final rule, DOE shifted the baseline modeled efficiencies to match the tested values described above. Similarly, subsequent, more efficient designs were shifted by the same percentage change in losses as the baseline shifts. For example, the baseline polyphase model in the design software predicted an efficiency of 77.7 percent. This value was decreased to the average tested efficiency value of 75.3 percent, constituting an increase in motor losses of roughly 14 percent. The modeled efficiencies of the more efficient designs were then shifted down in efficiency by a 14 percent increase in motor losses as well.
Table IV.5—Efficiency Values of Baseline Models
Polyphase
1 hp, 4 pole
CSIR
1/2
hp, 4 pole
CSCR
3/4
hp, 4 pole
Catalog Rated Efficiency (%)
74.0
59.0
72.0
Software Modeled Efficiency (%)
77.7
57.9
70.7
Baseline/Tested Efficiency (%)
6
75.3
7
57.9
7
71.4
Shift in Losses from Modeled Values (%)
14
0
−3
In the NOPR, DOE stated that an accredited laboratory performed IEEE Standard 112 Test Methods A and B and IEEE Standard 114 to find efficiency data for its baseline models. However, at the public meeting on December 17,
2009, Baldor commented that according to NEMA and the National Voluntary Laboratory Accreditation
Program Handbook 150-10, accreditation is based on motor testing in accordance with IEEE Standard 112 Test Method B only, and that it does not currently cover testing in accordance with IEEE Standard 112 Method A or IEEE Standard 114. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 114-115) Therefore, Baldor suggested that DOE's statement about motor tests was misleading because no accreditation exists for two of the three listed methods. DOE clarifies its previous statement to say that a laboratory accredited to perform IEEE Standard 112 Test Method B performed the tests.
6
This efficiency represents the average of tests conducted on six separate units of the same model number.
7
These values were incorrectly presented in the NOPR as 57.7 and 71.0 for CSIR and CSCR, respectively. These values presented in the NOPR represent the NOPR modeled efficiencies. 74 FR 61427.
b. Baseline Temperature Rise
NEMA MG1 defines several temperature rise requirements for general purpose alternating current single-speed induction motors. In the NOPR TSD, DOE reported the modeled temperature rise characteristics of the baseline motors selected in the engineering analysis. In response to those values, Baldor reasoned that because the reported temperature rises (78 °C for the polyphase motor and 86 °C for the CSIR motor at full load) would far exceed the NEMA temperature rise limit of 70 °C at service factor load, for a Class A motor, the selected baseline motors were inappropriate selections. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 27-30) After receiving Baldor's comments, DOE reviewed the data from thermal tests conducted on the purchased baseline motors and found that the winding temperature tests indicated that all three baseline motors in fact meet NEMA temperature rise requirements for Class A insulation systems. See chapter 5 of the TSD for the tested temperature rise data for each baseline motor. However, because the modeled temperature rises in the design software were inconsistent with these tests, DOE revised the operating temperature inputs to the design software to agree with the tested temperature rise data. This change in operating temperature results in slight changes in the baseline modeled efficiencies. Namely as operating temperature decreases, motor efficiency generally increases. Though these motors meet temperature rise requirements for Class A insulation systems, DOE emphasizes again, that its scope of coverage is not bound to those motors with temperature rises of less than Class A requirements, but rather motors that contain insulation class systems rated A or higher.
c. Baseline Motor Performance
In the NOPR TSD, DOE presented the modeled performance characteristics for the baseline motors selected. Baldor and NEMA both commented that none of the baseline motors meet all of the general purpose performance characteristics for locked-rotor torque, locked-rotor
current, and breakdown torque as defined in NEMA MG1-1987. They argued that these motors cannot be considered small electric motors (under the statutory definition) and therefore, should have never been chosen as baseline motors. For polyphase motors, they cited comparisons to performance characteristics in NEMA MG1-1987 intended for “medium” motors. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 64-67; NEMA, No. 24 at pp. 7-8) The NEEA/NPCC disagreed and stated that because the performance of the motors selected by DOE were representative of products on the market, they were appropriate baseline models. (NEEA/NPCC, No. 27 at pp. 8-9)
DOE examined the performance characteristics of the three baseline motors, and determined that they meet all small electric motor performance requirements of NEMA MG1. Thus, DOE believes that they are appropriate baseline motors and are representative of covered small electric motors on the market. Table IV.6 below presents references to NEMA MG1-1987 sections containing performance characteristics that DOE believes are relevant to single-phase and polyphase small electric motors.
Table IV.6—NEMA MG1-1987 Performance Requirements Relevant to General Purpose Small Motors
Single phase
Polyphase
Breakdown Torque
12.32.1
12.37.
Locked Rotor Current
12.33.2
None.*
Locked Rotor Torque
12.32.2
None.
* Because NEMA MG1-1987 section 12.35 is labeled as applying to only medium motors, DOE does not believe there are polyphase locked rotor current requirements for small motors. However, NEMA commented at the preliminary analysis stage that it is common industry practice to use the limits for Design B medium motors for small motors. (NEMA. No. 13, p. 6).
DOE notes that in the NOPR TSD, DOE presented these performance characteristics at full load, steady state operating temperature. When extrapolated down to an ambient temperature of 25° C, the temperature at which NEMA specifies that breakdown torque requirements must be met, all baseline motors meet the necessary small motor performance requirements in MG1. A direct comparison of those values, as requested by Baldor (Baldor, No. 25 at p. 2; Baldor, Public Meeting Transcript, No. 20.4 at p. 66) is available in TSD chapter 5.
3. Higher Efficiency Motor Designs
After establishing baseline models, DOE next used the motor design software to incorporate design options (generated in the market and technology assessment and screening analysis) to increase motor efficiency. In response to the NOPR engineering analysis, DOE received several comments that addressed issues regarding the application of the design options in the engineering analysis and the validity of the results outputted from the design software.
In general, manufacturers questioned whether DOE adequately verified that its design software accurately predicts motor efficiency. NEMA and Baldor stated that DOE seemingly used an AEDM to generate motor designs and scaled efficiencies for other product classes without meeting DOE's own substantiation requirements of an AEDM. Emerson stated that in order for manufacturers to use an AEDM for compliance and certification with energy conservation standards, DOE requires that the AEDM must be applied to 5 basic models of small electric motors, and it be shown to accurately predict motor efficiency under real-world testing. Collectively, this constitutes a total of 25 tests manufacturers must complete in order to verify their design software. (Emerson, Public Meeting Transcript, No. 20.4 at p. 105) Baldor and NEMA contended that DOE must be held to these same verification standards if it uses an AEDM in establishing energy conservation standards. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 118-24, 145-146; NEMA, No. 24 at p. 11-12)
NEEA/NPCC disagreed with these comments, stating that requirements of certification and compliance with Federal efficiency regulations are wholly unrelated and inapplicable to DOE's analysis methodology. The motor design software used in the engineering analysis was simply being used to create motor models for analysis, not as an alternative compliance tool. Thus, DOE is under no obligation to meet the verification standards of an AEDM. NEEA/NPCC stated that based on the description of the design software, the technical qualifications of the consultants, and the motor testing and teardowns conducted to verify the accuracy of software tools, it has satisfied with DOE's engineering analysis methodology. (NEEA/NPCC, No. 27 at pp 6-7).
DOE agrees with NEEA/NPCC that substantiation of an AEDM is a concept intended for certifying compliance with energy efficiency standards. It is a tool for manufacturers to use to help ensure that equipment they manufacture comply with the standards that DOE sets. It is not a tool for assessing whether a particular energy efficiency level under consideration by DOE satisfies the EPCA criteria. Accordingly, the use of the AEDM in the manner suggested by industry would not be relevant for the purposes of this engineering analysis, which is geared toward DOE's standards rulemaking.
Moreover, on the bases of the baseline motor efficiency verification process which included physical teardowns for numerous small motors, DOE has confidence in the software program it has selected and believes it to be appropriate to analyze efficiency levels for small electric motors.
8
Though the supporting data for these tests are based on confidential manufacturer data, the performances of these motors verify the software predictions.
8
DOE notes that the software used for its analysis has been employed by numerous motor manufacturers to develop designs that have then been used to produce lines of motors, including capacitor-start and polyphase motors.
In addition, as discussed in the NOPR, to the extent that it was feasible, DOE substantiated the resulting cost-efficiency curves by testing and tearing down higher efficiency motors. In response to that NOPR discussion, NEMA asserted that as seen in Table 12.1 and Table 12.2 in appendix 5A of the NOPR, DOE did not compare the test results to the calculated results for the representative product classes. (NEMA, No. 24 at p. 24) DOE wishes to clarify that Table 12.1 and Table 12.2 in appendix 5A of the NOPR TSD contained test results for motors that were used as part of DOE's scaling methodology. The results of the cost-efficiency curve validation testing for representative product classes are shown in Figure 4.1 through Figure 4.3 of appendix 5A of the NOPR and final rule TSDs.
a. Electrical Steel
In the NOPR engineering analysis, DOE modeled the use improved grades of electrical steel and thinner laminations to achieve higher motor efficiency. In response to that analysis Baldor and NEMA commented that because DOE's design software bases loss calculations on Epstein core loss values, they believe DOE's modeled efficiencies using improved steel types may overestimate the actual achievable efficiency for a particular motor design. Baldor cited its experience with building and testing multiple motors using various steel types, stating that it has never been shown that the core loss in a motor with round laminations and rotating flux field is directly related to the results of Epstein testing. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 276-80, Baldor, No. 25 at pp. 5-7; NEMA, No. 24 at pp. 23-24) As a result, Baldor asserted that DOE should not rely on steel manufacturer core loss data unless it is able to produce an actual motor to verify its design assumptions. (Baldor, Public Meeting Transcript, No. 20.4 at p. 277) NEEA/NPCC encouraged DOE to investigate the claims made by Baldor at the public meeting and revise the engineering analysis if necessary. (NEEA/NPCC, No. 27 at pp. 9-10)
DOE recognizes that in analyzing motor performance, calculated core losses based on Epstein tests may deviate from actual core losses in the motor.
9
This is primarily due to the harmonic effects created by the distortion of the flux density waveform. When motor core losses are modeled or measured at solely the fundamental frequency, it is possible that additional losses due to these harmonics may not be accounted for, which may yield an overall underestimation of losses. While DOE acknowledges that this phenomenon exists, DOE also believes it has accounted for this effect in its analysis.
9
Epstein tests are performed by steel manufacturers to determine expected core loss values in electrical steel. The results of these tests are usually provided by steel manufacturers and are used by motor design engineers to predict motor performance.
As Baldor suggests, one way to ensure that a software model is calibrated correctly to account for effects such as these is to build prototype motors and examine their performance characteristics. Though DOE did not perform such an exercise specifically for this rulemaking, the design software DOE employed for this analysis has been used in the past to design many small motors, whose performance characteristics compare favorably with the model predictions. Baldor did not provide any additional data from which DOE could refine its analysis or perform sensitivity analyses, even though it stated the values of core loss used in DOE's software model were inaccurate.
DOE believes that the variances between Epstein losses and actual motor losses are not an issue for its engineering analysis. It is DOE's understanding that the Epstein core loss data begin to vary significantly from actual motor core losses when various components of the core steel are driven into magnetic saturation. Magnetic saturation is when the amplitude of the magnetic field excitation is large enough to force the flux density (of the magnetic field) into the nonlinear region of the B-H curve. At this point the harmonic components of the electromagnetic field increase.
10
As these harmonic components increase, motor efficiency may be adversely affected and predicted core losses from the Epstein tests will deviate from actual core losses seen in the motor. In order to assess the degree to which these harmonic effects may impact the efficiency of motors analyzed in the engineering analysis, DOE examined the magnetic flux densities at full-load for each motor design. By using steel manufacturer-provided magnetization curves, DOE first determined the saturation point for each of the lamination types. DOE then evaluated each of its motor designs to determine whether it operates near magnetic saturation. The results of this analysis indicated that only two motor designs, the CSIR baseline design and the polyphase efficiency level (EL) 1 design, operate close to the point of magnetic saturation at full load. Based on these results, DOE believes that for all other motor designs, reliance on the Epstein core loss data is appropriate to model motor efficiency.
10
Yamazaki, Katsumi; Watanabe, Yuta. “Stray Load Loss Calculation of Induction Motors Using Electromagnetic Field Analysis.” IEEJ Transactions on Industry Applications, Volume 128, Issue 1, pp. 56-63.
DOE recognizes that for motors designs operating near the point of magnetic saturation (
i.e.,
CSIR baseline and polyphase EL 1 designs), the modeled efficiency might deviate from a tested efficiency if a prototype were built. With regards to the CSIR baseline design, DOE notes that, as discussed in section IV.C.2.a, the efficiency associated with that design was based on a tested efficiency, rather than a modeled efficiency. Therefore, the baseline efficiency for the CSIR motor should adequately account for any harmonic core loss effects. For the polyphase EL 1 design, DOE recognizes that there may be significant uncertainty in its modeled efficiency. However, as discussed in section VI DOE has found that an efficiency level higher than EL 1 is technologically feasible and economically justified based on the net benefits to the nation and individual consumers. Therefore, DOE's standards-setting decisions in this final rule are not dependent on any uncertainties associated with the polyphase EL1 motor design. Please refer to TSD chapter 5 for additional information regarding the steels used in DOE engineering analysis, their respective saturation levels, and the flux densities of the designs using those steels.
Baldor also questioned the validity of using several higher efficiency steel types in small motors, citing an AK steel publication. Baldor commented that several of the lamination types modeled, namely 24M19 and 29M15, are not recommended for use in motors with less than a 100 horsepower rating. (Baldor, No. 25 at p. 7) DOE has reviewed the referenced AK Steel publication
11
and disagrees with Baldor's assertion. The AK Steel publication does not suggest that 24M19 and 29M15 steels should not be used in motors with less than a 100 horsepower rating; rather it only indicates that small electric motors currently on the market do not typically use these steel grades. In addition, DOE has not received any comments explaining why these lamination types, commonly used in medium motors, would not be applicable to small electric motors. Therefore, in this final rule, DOE continues to use higher efficiency steel grades and thinner laminations in the engineering analysis.
11
AK Steel Product Data Bulletin. Nonoriented Electrical Steels.
http://www.aksteel.com/pdf/markets_products/electrical/Non_Oriented_Bulletin.pdf.
b. Thermal Analysis
NEMA and Baldor also questioned whether a thermal analysis was conducted for the higher efficiency motors modeled, stating the importance of verifying the thermal viability of motor designs. (NEMA, No. 24 at pp. 6-7, Baldor, Public Meeting Transcript, No. 20.4 at pp. 28-29) Emerson commented that the NOPR analysis disregarded MG1 performance requirements, including operating temperatures, potentially cause conflicts with the National Electrical Code. (Emerson, No. 28, p. 2) In response to these comments, DOE has refined its thermal analysis methodology to ensure that it is accurately modeling motor efficiency and that all motor designs
evaluated are thermally viable. As mentioned in section IV.C.2.b, to establish the baseline motors' operating temperatures, DOE conducted tests in accordance with the relevant IEEE test procedures and monitored the temperature rises of the motors. DOE was then able to calculate a thermal resistance for each of the baseline motors. The thermal resistance of each subsequent design was modified to reflect the improved thermal transfer of the more efficient design. As each higher efficiency design was modeled, DOE calculated a new temperature rise. These calculations indicate that as motor efficiency increases (through an increase in the amount of active material and decrease in I
2
R losses
12
), the temperature rise of the motor continually decreases. For this reason, DOE believes that all higher efficiency motor designs analyzed in the engineering analysis have lower temperature rises than their respective baseline motors and are thermally viable. See TSD chapter 5 for additional information regarding the actual temperature rises calculated for each of DOE's designs.
12
I
2
R losses refer to resistive losses, stemming from current flow through the copper windings in the stator and conductor bars in the rotor and manifest as waste heat which adversely affects the efficiency of a motor.
c. Performance Requirements
As discussed in section IV.C.2.c, NEMA, through its MG1 publication, lays out a number of performance requirements (breakdown torque, locked rotor torque, and locked rotor current) that motors must meet in order to be considered “general purpose.” In response to the small electric motor designs presented in the NOPR, manufacturers commented that some of DOE's more efficient designs do not meet certain performance requirements. Emerson added that many of the design changes that would be necessary to meet these requirements, such as increasing resistance at locked rotor or increasing the number of turns of the stator coils, could actually decrease efficiency. (Baldor, No. 25 at p. 4; Baldor, Public Meeting Transcript, No. 20.4 at pp. 67, 86-87; Baldor, No. 25 at pp. 1-3; Emerson, Public Meeting Transcript, No. 20. 4 at pp. 192-93; Emerson, No. 28, p. 1) Emerson also noted that the costs for the designs might increase when the motors are adjusted to meet these performance characteristics. (Emerson, Public Meeting Transcript, No. 73) In light of these comments, DOE revisited its engineering designs and found that when new performance values were calculated at operating temperatures of 25 °C (as was done for the baseline designs), the vast majority of motors met applicable NEMA standards. For the motors that did not meet breakdown torque, locked rotor torque, or locked rotor current requirements (as presented in TSD Chapter 5), DOE revised these designs such that they adhered to all performance requirements. DOE notes that in some cases, as predicted by manufacturers, the design revisions led to increases in costs to maintain the same level of efficiency. See Chapter 5 of the TSD for further details on the performance characteristics of motor designs analyzed in the engineering analysis and comparisons to NEMA performance requirements.
Baldor also noted that many small electric motors are rated in a broad voltage range (208V to 230V) and asserted (without clarifying) that the NEMA standard specifies these motors must be able to meet NEMA performance requirements over the entire voltage range. Baldor questioned whether DOE's proposed efficiency levels are achievable when motors are operated across this entire voltage range (specifically at 208V). (Baldor, Public Meeting Transcript, No. 20.4 at pp. 271-72) As indicated by Emerson (Emerson, Public Meeting Transcript, No. 20.4 at pp. 273-74), it is DOE's understanding the 208V rating constitutes an unusual service condition. Thus, DOE's engineering analysis was based on motor operation at 230V.
DOE notes that although the NEMA standard may require that certain performance characteristics (such as breakdown torque) be met through the entire rated voltage range, there is no such requirement for Federal efficiency standards. In fact, DOE's test procedures for small electric motors, IEEE 112 (Section 6.1) and IEEE 114 (Section 8.2.1) state that efficiency shall be determined at the rated voltage, without specifying which voltage shall be used in cases where motors are rated with broad voltages or dual voltages. DOE understands that it is at the manufacturer's discretion under which single voltage condition to test its motor. Because the test procedure outputs an efficiency value at a single input voltage, DOE did not conduct an additional analysis at 208V.
Baldor and NEMA stated that MG1 has additional requirements for small electric motors such as voltage unbalance, variation from rated speed, occasional excess current, stall time, overspeed, and sound quality. (Baldor, No. 25 at p. 3; NEMA, No. 24 at p. 9) In examining the variation from rated speed requirements, DOE notes that these are only applicable to medium motors, and thus not relevant to DOE's small electric motor designs. With regard to the other specifications, DOE believes that because it purchased the baseline motors from NEMA manufacturers, it is reasonable to assume that the motors meet NEMA MG1 requirements.
In addition DOE has evaluated each of its motor designs and believes for the following reasons that because the baseline motors likely meet all specifications, then the higher efficiency motors are expected to meet them as well. Specifically, whether a motor is able to meet voltage unbalance, excess current, and stall time requirements is often related to whether a motor overheats at those specified conditions. As the I
2
R losses in higher efficiency motors modeled are generally lower than that of the baseline motors (thus, resulting in a lower temperature rise), DOE believes that overheating effects will not be exacerbated with higher efficiency.
For the overspeed requirement, DOE understands that there are several mechanical failure modes that may cause the motor to be unable to withstand speeds above the rated speed. Two primary reasons are the failure of the motor bearings and the potential for the motor shaft to bend, causing the rotor and stator to contact. In addition, DOE understands this issue to be more problematic for medium motors (with larger inertia) than small motors. Finally, for sound quality, decreased current and magnetic flux densities in higher efficiency motors will likely cause the magnitude of the torque pulsations of the motor to decrease during running conditions, reducing noise. The added mass of higher efficiency motors also serves as a dampener to reduce motor vibrations and noise. Given all of these reasons, DOE believes that all motor designs analyzed in the engineering analysis meet the additional performance requirements identified by the commenters.
DOE also received comments at the public meeting regarding the power factor associated with its designs. Baldor commented that during the preliminary analysis stage of the rulemaking some parties preferred that the power factor levels be above 85 percent, but that DOE's analyses utilized a power factor around 71 to 73 percent for polyphase motors. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 275-76) As discussed in the NOPR, DOE understands that sacrificing power factor to obtain gains in efficiency is counterproductive because of the
negative effects on line efficiency. 74 FR 61429 For this reason, DOE maintained or increased the power factor of the baseline motor for each more efficient design. While power factor is generally considered when evaluating the potential benefits related to a particular efficiency level, it is not a design option that necessarily improves the energy efficiency of small electric motors. Increasing power factor could yield results that reduce the energy efficiency of individual units or impose higher costs without an increase in energy efficiency. For this reason, DOE opted not to require its designs to have an 85 percent power factor in its design analysis.
d. Stray Load Loss
In the NOPR, DOE presented values of stray load loss that were modeled in the design software for the baseline and higher efficiency motor designs. The polyphase designs had a value of 2.4 percent for stray load loss, while the CSIR and CSCR designs had a value of 1.8 percent. In response to the NOPR, DOE received several comments regarding the stray load loss values used in its designs. Baldor commented that in the absence of a tested stray load loss value, the IEEE Standard 112 Test Method A (which is referenced as the DOE test procedure for polyphase motors of 1-horsepower or lower) indicates that a value of 1.8 percent should be used. As a result, Baldor questioned the source of DOE's polyphase motor stray load loss value. Baldor was concerned that DOE actually performed IEEE Standard 112 Test Method B, which calculates stray load loss but may yield a different tested efficiency value than Test Method A. In Baldor's view, using Test Method B could potentially skew the analysis. (Baldor, Public Meeting Transcript, No. 20.4 at pp. 280-82; NEMA, No. at pp. 23-24)
Baldor and NEMA also questioned why the stray load loss value of 1.8 percent was used for the single-phase motors when the IEEE Standard 114 test procedure calls for a measurement of stray load losses. (Baldor, Public Meeting Transcript, No. 20.4 at p. 282; NEMA, No. 24 at p. 24) They were concerned that DOE did not follow the IEEE Standard 114 test procedure for the single-phase motors since the stray load loss value used did not appear to be a measured value. (Baldor, Public Meeting Transcript, No. 20.4 at p. 286) Advanced Energy supported DOE's assumptions, commenting that even though IEEE Standard 114 calls for a separation of losses, it also allows an assumed stray load loss value of 1.8 percent when a measured value cannot be determined. (Advanced Energy, Public Meeting Transcript, No. 20.4 at pp. 285-87) NEEA/NPCC also commented that DOE's stray load loss assumptions were appropriate. (NEEA/NPCC, No. 27 at p. 10)
To clarify, DOE tested the polyphase baseline motor according to both the IEEE Standard 112 Method A and Method B test procedures. While Method A is the appropriate DOE test procedure for a 1-horsepower, four-pole small electric motor, Method B determines efficiency by segregating motor losses. When DOE compared the results of Method A and Method B, it found that there was no material difference between the resulting tested efficiencies for this particular motor. Therefore, DOE assumed that it would be most accurate to model the stray load losses determined by IEEE Standard 112 Method B (
i.e.
2.4 percent) rather than an assumed value (
i.e.
1.8 percent).
The two baseline single-phase motors were tested according to IEEE Standard 114. As stated by Advanced Energy, the IEEE Standard 114 test procedure provides that if stray load loss is not measured, then the value of stray load loss at rated load may be assumed to be 1.8 percent of the rated load, consistent with DOE's assumption for CSCR and CSIR motors. DOE recognizes that losses can be segregated using the IEEE Standard 114 test procedure and therefore also calculated the stray load losses for the baseline motors. The results of these tests showed that the stray load losses for the CSIR and CSCR baseline motors were 1.8 percent and 1.7 percent. Given the similarity to IEEE Standard 114 assumed value and NEMA's previous recommendation to use this value, DOE believes that the use of 1.8 percent stray load loss for the single-phase motors was appropriate and has used it again for today's final rule.
Additionally, NEMA and Baldor questioned DOE's decision to maintain a constant stray load loss across its designs within a representative product class, stating that it would be unlikely that the use of thinner electrical steels in a longer core length would have resulted in the same level of stray load loss as in the baseline design. (NEMA, No. 24 at p. 24; Baldor, Public Meeting Transcript, No. 20.4 at pp. 281-83) In response, DOE affirms that its assumptions of stray load loss for higher efficiency motor designs are appropriate. DOE recognizes that several factors, such as manufacturing process and harmonic effects, may affect the quantity of stray load loss for a particular motor. However, as discussed earlier, DOE has determined that the majority of motor designs evaluated operate below the point of magnetic saturation, thus reducing the impact of harmonic effects. Additionally, DOE understands that it is common practice for motor design engineers to assume a value of stray load loss either based on experience or as recommended by IEEE test procedures when creating new, potentially more efficient, motor designs. Finally, DOE also notes that both the polyphase and single-phase IEEE test procedures provide precedent for the assumption of constant stray load losses across several motor designs.
e. Stack Length and Core Diameter
In the NOPR, DOE considered an increase in stack length as a viable option for increasing motor efficiency. DOE recognized, however, that limitations for certain motor applications exist because an increase in stack length may cause the motor to exceed the space constraints of the application into which it would reside. Thus, DOE followed a suggestion made by NEMA during the preliminary analysis stage and limited the stack length increases for space-constrained applications to no more than a 20 percent increase over the baseline motor. (NEMA, No. 13, at p. 4) For applications that DOE considered non-space constrained, the stack length of the motor was allowed to increase by up to 100 percent of the stack length of the baseline motor (
i.e.
it could double).
In response to the NOPR analysis, several interested parties commented on DOE's assumptions of space constraints and stack length increases. WEG questioned if the 20 percent increase in stack length for space constrained applications is an appropriate tolerance. (WEG, Public Meeting Transcript, No. 20.4 at p. 83) A.O. Smith commented that doubling the stack length in non-space constrained applications will be somewhat impractical for customers' applications. (A.O. Smith, Public Meeting Transcript, No. 20.4 at p. 81).
In response to the manufacturers' comments, DOE maintains that the 20 percent increase in stack length for space-constrained applications that was used in the NOPR is still an acceptable tolerance. DOE notes that NEMA reiterated its support for this design constraint in its comments responding to the NOPR, by citing its recommendation from the preliminary analysis. (NEMA, No. 24 at p. 9) Regarding doubling the stack length of the motor, DOE also believes this is an appropriate tolerance for non-space constrained applications. When DOE solicited engineering cost-efficiency
curves from manufacturers for the preliminary analysis, all participating manufacturers suggested that increasing stack height would be one of the first design options used to achieve greater efficiencies because of the relative cost of this design option versus a change in steel type lamination. In designs provided by all of these manufacturers, stack increases of well over 100 percent relative to the baseline were used to achieve target efficiency levels that DOE provided to manufacturers. Accordingly, DOE believes that for those applications that are non-space constrained, a stack increase of 100 percent is an appropriate and even a likely design option that manufacturers could employ. DOE accounts for the costs associated with increasing a motor's stack length in markups analysis (see section IV.D).
Emerson also commented that the NOPR efficiency levels would require several motors to increase in frame size. (Emerson, No. 28 at p.1) However, DOE disagrees with Emerson's comments and notes that for all higher efficiency designs developed in the engineering analysis, core diameter was held constant to the baseline value. As only an increase in core diameter would force a frame size increase, DOE believes that all efficiency levels analyzed can be achieved without increasing frame size.
4. Cost Model
For the NOPR engineering analysis, DOE estimated the manufacturing production cost (MPC) of small electric motors by using outputs of the design software to generate a complete bill of materials. The bill of materials was marked up to account for scrap, overhead (which includes depreciation) and associated non-production costs such as interest payments, research and development, and sales and general administration. To account for the increased depreciation of equipment associated with manufacturing a copper rotor, DOE used separate overhead markups for motor designs using copper and aluminum rotors. The software output also included an estimate of labor time associated with each step of motor construction. DOE multiplied these estimates by a fully burdened labor rate to obtain an estimate of labor costs.
DOE estimated input costs by using an inflation-adjusted 5-year average of prices for each of the input commodities: Steel laminations, copper wiring, and aluminum and copper for rotor die-casting. This method for calculating costs is consistent with past rulemakings where material costs were a significant part of manufacturers' costs. In calculating the 5-year average prices for these commodities, DOE adjusted historical prices to 2008 terms using the historical Producer Price Index (PPI) for that commodity's industry. For this final rule, DOE updated material prices using the PPI to reflect 2009$. After calculating the MPC, DOE applied a 1.45 manufacturer markup to arrive at the MSP.
Emerson commented that it was concerned that DOE had not appropriately accounted for the significant costs associated with implementing the technology to manufacture motors with copper die-cast rotors in the engineering analysis. (Emerson, Public Meeting Transcript, No. 20.4 at p. 94) DOE recognizes that there are additional costs associated with implementing copper die-cast rotors and has incorporated higher depreciation costs in the Engineering Analysis for designs requiring this technology.
With regard to the accounting of higher depreciation for equipment used to manufacture copper die-cast rotors, NEEA/NPCC supported DOE's approach to using different overhead markups for designs with copper rotors and those with aluminum rotors. (NEEA/NPCC, No. 27 at p. 9) NEMA commented that since motor manufacturers typically standardize its production process for a product line, the higher overhead attributable to the application of advanced technologies will be applied over all production unless the manufacturer exits that portion of the market. (NEMA, No. 24 at p. 9) As all comments supported the use of higher markups when manufacturing copper rotors, DOE maintained this approach in the engineering analysis for the final rule. See section IV.C.4 for further details.
5. Efficiency Scaling
For the NOPR, in order to scale efficiency levels from the representative product classes to the other product classes, DOE used data on commercially-available motors to investigate how changing horsepower or pole configuration affects efficiency, DOE evaluated product lines of different manufacturers separately. In developing these efficiency relationships, DOE considered only motors of the most restrictive frame size for a given product class to ensure that the most dimensionally-constrained motors on the market would be able to meet all efficiency levels derived. DOE then converted these efficiency relationships across product class into motor loss relationships. DOE applied these relationships (as a percentage change in motor losses) to each efficiency level analyzed for the representative product classes, ultimately deriving corresponding efficiency levels for product classes not directly analyzed in the engineering analysis. DOE repeated this analysis for each manufacturer's product line for which sufficient data were available. Finally, DOE averaged the results based on each of the manufacturer's product lines to obtain aggregated scaled efficiency levels for all product classes.
DOE received several comments on the results and methodology of the proposed scaling analysis. While NEAA/NPCC supported DOE's scaling methodology (NEEA/NPCC, No. 27 at p. 9), Baldor stated that the scaling presented is likely not accurate because of the difficulty in predicting efficiencies when changing frame sizes, horsepower, and pole configurations. Instead, Baldor commented that DOE should create a motor design for each non-representative product class to verify the scaled efficiencies. (Baldor, Public Meeting Transcript, No. 20.4 at p. 97; Baldor, No. 25 at p. 8) WEG also commented that the scaling should take into account not only the change in efficiency associated with altering horsepower or pole configuration, but also the drop in efficiency associated with moving from a 56-frame to a 48-frame, and potentially a smaller core diameter. (WEG, Public Meeting Transcript, No. 20.4 at p. 220)
In addition, with regard to the polyphase motor scaling, several manufacturers pointed to the efficiencies at high horsepower ratings as evidence that DOE scaling was flawed. Specifically, they remarked that although the proposed level for the representative polyphase product class harmonized with medium motor NEMA Premium efficiency standards, the 3-horsepower, six-pole polyphase motor had a scaled efficiency greater than the NEMA Premium level.
13
They also noted that because the comparable medium motor for that product class is built in a 213 T-frame (larger than a 56-frame), it may be unreasonable to require a 56-frame motor to have a higher efficiency. (A.O. Smith, No. 26 at p. 2; Baldor, No. 25 at p. 8; Baldor, Public Meeting Transcript, No. 20.4 at pp. 100-101, 212-213; Regal-Beloit,
Public Meeting Transcript, No. 20.4 at pp.105)
13
NEMA Premium refers to efficiency levels for three-digit frame series medium electric motors developed by NEMA to identify high efficiency motors. Congress subsequently adopted those levels for medium electric motors. See EISA 2007, Sec. 313(b).
DOE agrees that the efficiency behavior at high horsepower ratings for polyphase motors indicated a lack of accuracy in the NOPR scaling, and has revised its analysis for the final rule. Baldor's recommendation to generate motor designs to validate scaling essentially constitutes developing an additional engineering analysis for every product class, which is atypical for DOE rulemakings and unnecessary because it defeats the purpose of using a scaling methodology. In addition, DOE notes that in its comments on the preliminary analysis, NEMA recommended that DOE utilize product literature to derive efficiency levels for product classes not directly analyzed in the engineering analysis, which was a significant reason why DOE maintained a scaling approach based partially on publicly available data. (NEMA, No. 13, at p. 10) Thus, DOE believes scaling is an appropriate approach to developing efficiency levels. As interested parties did not recommend a new methodology for scaling, DOE based it revised scaling on the same general methodology (establishing relationships in efficiency across horsepower ratings and pole configurations), but utilized additional sources of data to refine its inputs.
One new source of data DOE utilized was the NEMA recommended standard levels for polyphase, CSIR, and CSCR motors built in small frames (42- and 48-frames) and in 56-frames. These recommended standard levels included efficiencies for motors with horsepower ratings less than and equal to 1-horsepower and with two-, four-, or six-pole configurations. (NEMA, No. 24 at p. 1) DOE first examined this data to see how it compared to the efficiency data of motors currently on the market. DOE noted that the efficiency relationships that NEMA presented between product classes were comparable to the market data that DOE had collected for the NOPR. For this reason, DOE concludes that NEMA's recommended standard levels can be used to establish appropriate efficiency (or loss) relationships for lower horsepower polyphase, CSIR, and CSCR motors.
For the high horsepower (greater than or equal to 1-horsepower) polyphase motors, DOE utilized the relationships found in the NEMA Premium standards for electric motors. As seen in Table IV.7, the majority of the NEMA Premium standards between 1- and 3-horsepower are based on motors with a frame size in the 140T series, which has the same foot to shaft dimension as the 56-frame motor. Therefore, for these 140T series product classes, DOE used NEMA Premium efficiencies to develop relationships across horsepower ratings and poles. DOE did not use the efficiency relationships found from NEMA Premium classes associated with larger frame sizes (182T). For these horsepower/pole configurations, DOE did not have sufficient efficiency data to determine appropriate scaling relationships. Thus, though efficiency generally increases with horsepower, in order to ensure that all efficiency levels are technologically feasible, DOE decided that the 3-horsepower, four-pole motor and 1
1/2
-horsepower, two pole motor would have the same minimum efficiency standards as the 2-horsepower, four-pole motor and 1-horsepower, two-pole motor, respectively.
Table IV.7—Frame Sizes Associated With NEMA Premium Standards
Motor horsepower/standard kilowatt equivalent
Six poles
Four poles
Two poles
1 hp/0.75 kW
56
143T
145T
1
1/2
hp/1.1 kW
143T
145T
182T
2 hp/1.5 kW
145T
145T
3 hp/2.2 kW
145T
182T
In the absence of any standardized efficiency levels above 1-horsepower for CSIR motors (such as those provided in the NEMA Premium table for polyphase motors), DOE continued to use market efficiency data. Since this approach, when used in the NOPR, resulted in some aberrations (abnormally high efficiencies) for high horsepower polyphase motors, DOE modified its methodology slightly for the final rule to result in more appropriate scaling relationships. As stated earlier, for the NOPR, because some manufacturers showed larger increases in efficiency with increasing horsepower than others, DOE averaged data from several manufacturer product lines to create efficiency relationships. However, for this final rule, to ensure the technological feasibility of all scaled efficiency levels, instead of averaging data from all manufacturers, DOE selected the product line which resulted in the most achievable efficiency levels.
As mentioned in the NOPR, DOE was unable to locate sufficient market data for CSCR motors. However, DOE data indicate that CSCR motors exhibit scaling relationships similar to CSIR motors. For these reasons, DOE decided to continue utilizing CSIR market data to characterize the efficiency (or loss) relationships present in the CSCR market at high horsepower ratings.
Next, DOE addressed changes in physical dimensions of motors across horsepower ratings and pole configurations. As discussed earlier, DOE recognizes that core diameter affects the amount of active material that is used to reduce motor losses, thus impacting efficiency. If DOE were to set a standard based on an analysis of a motor of larger core diameter, it could potentially eliminate smaller core diameter motors from the market. Therefore, after establishing the efficiency relationships (by using the NEMA recommended levels, the NEMA Premium levels, and market data), DOE accounted for the fact that for some horsepower/pole configurations, 48-frame size motors are commercially available, while for others, only 56-frame size motors are commercially available.
As stated by WEG at the NOPR public meeting, a reduction in frame size (or core diameter) should accompanied by a reduction in efficiency. To determine the appropriate efficiency reduction of shifting from a motor with a core diameter representative of a 56-frame to a core diameter representative of a 48-frame, DOE again utilized the NEMA recommended efficiencies. From these efficiency values, DOE noted that according to NEMA a shift in frame size constitutes approximately a 20 percent change in losses. DOE applied this 20 percent reduction in losses to product classes for which 42 frame or 48-frame motors are commercially available. DOE intends for its loss scaling analysis to reflect motors in the smallest commercially available frame size for each product class.
After deriving efficiency relationships accounting for changes in horsepower, pole configuration, and core diameter, DOE then applied these relationships (as a percentage change in motor losses)
to each efficiency level of the representative product classes, ultimately deriving corresponding efficiency levels for the non-representative product classes.
6. Cost-Efficiency Results
The results of the engineering analysis are reported as cost-efficiency data (or “curves”) in the form of MSP (in dollars) versus full-load efficiency (in percentage). These data form the basis for subsequent analyses in the final rule. As discussed in the NOPR, DOE developed two curves for each product class analyzed, one for the space-constrained set of designs restricted by a 20-percent increase in stack height and one for the non-space constrained set of designs restricted by a 100-percent increase in stack height relative to the baseline.
NEMA recommended efficiency levels for small electric motors that it believed would be technologically feasible to implement by 2015. NEMA presented six separate sets of efficiency levels, one for 56-frame size motors in each of the three motor categories and one for 42- and 48-frame size motors in each of the three motor categories. (NEMA, No. 24 at p. 1) When DOE revised its engineering analysis, it ensured that each of its representative units had an efficiency level that corresponded to one of those sets of standards. For CSIR motors, NEMA proposed an efficiency value of 72.0 percent for a 48-frame size, four-pole
1/2
-horsepower motor. This proposal roughly corresponds to DOE's efficiency level 4 for CSIR motors. For CSCR motors NEMA proposed an efficiency value of 80.0 percent for a 56-frame size, four-pole,
3/4
-horsepower motor. This proposal corresponds to DOE's efficiency level 2 for CSCR motors.
For polyphase motors, NEMA did not present an efficiency value for the four-pole, 1-horsepower product class. In light of this, DOE utilized its scaling model to identify the projected efficiency for the four-pole, 1-horsepower product class according to NEMA's recommendations for the 42- and 48-frame size motors. DOE used the 42/48-frame size proposed levels to apply to its representative product class because the core diameter of its baseline model is representative of 48-frame size motors. DOE projects this efficiency value to be approximately 82.6 percent for the representative polyphase motor. As this efficiency lies between the designs analyzed for EL 4 and EL5, DOE created an additional efficiency level at 82.6 percent, denoted EL 4b. DOE developed a new space constrained and non-space constrained design at this efficiency level that adhered to all of DOE's design limitations.
Table IV.8 through Table IV.10 show the efficiency value and manufacturer selling price data for each EL examined in the final rule.
Table IV.8—Efficiency and Manufacturer Selling Price Data for Polyphase Motor
Efficiency level
Efficiency
(%)
(Design 1/Design 2) *
Manufacturer selling price
($)
(Design 1/Design 2) *
Baseline
75.3
98.54
EL 1
77.3
104.83
EL 2
78.8
108.17
EL 3
80.5
114.24
EL 4
81.1
118.54
EL 4b
83.5/83.5
135.62/134.04
EL 5
85.3/85.2
230.92/153.92
EL 6
86.2/86.3
237.70/186.37
EL 7 (Max-tech)
87.7/87.8
1,766.06/326.18
* Design 1 denotes the space-constrained design, and Design 2 denotes the non-space-constrained design. If only one value is listed, then the space-constrained design is the same as the non-space-constrained design.
Table IV.9—Efficiency and Manufacturer Selling Price Data for Capacitor-Start, Induction-Run Motor
Efficiency level
Efficiency (%)
(Design 1/Design 2) *
Manufacturer selling price ($)
(Design 1/Design 2) *
Baseline
57.9
91.24
EL 1
61.1
95.43
EL 2
63.5
98.45
EL 3
65.7
99.58
EL 4
70.6/70.5
114.31/106.99
EL 5
71.8/71.8
117.07/118.00
EL 6
73.1/73.3
182.09/132.22
EL 7 (Max-tech)
77.6/77.7
1,200.98/151.25
* Design 1 denotes the space-constrained design, and Design 2 denotes the non-space-constrained design. If only one value is listed, then the space-constrained design is the same as the non-space-constrained design.
Table IV.10—Efficiency and Manufacturer Selling Price Data for Capacitor-Start, Capacitor-Run Motor
Efficiency level
Efficiency
(%)
(Design 1/Design 2) *
Manufacturer selling price
($)
(Design 1/Design 2) *
Baseline
71.4
111.72
EL 1
75.1
117.13
EL 2
79.5/79.5
137.20/129.88
EL 3
81.7/81.8
142.63/135.56
EL 4
82.8/82.8
146.44/142.76
EL 5
84.1/84.0
154.55/151.91
EL 6
84.8/84.6
236.98/158.25
EL 7
86.8/86.7
244.03/175.75
EL 8 (Max-tech)
88.1/87.9
1,771.47/327.69
* Design 1 denotes the space-constrained design, and design 2 denotes the non-space-constrained design. If only one value is listed, then the space-constrained design is the same as the non-space-constrained design.
D. Markups To Determine Equipment Price
To calculate the equipment prices faced by small electric motor purchasers, DOE multiplied the manufacturing costs developed from the engineering analysis by the supply chain markups it developed (along with sales taxes). In the NOPR, DOE explained how it developed the distribution channel markups used. 74 FR 61434.
DOE did not receive comments on these markups; however, in written comments, NEMA and DOJ commented that some original equipment manufacturers (OEMs) could incur additional design costs to redesign their products to accommodate the increased size of more efficient motor designs. (NEMA, No. 24 at p.19 and DOJ No. 29 at p. 2) DOE recognizes that motors produced following the introduction of the standards described in this rule will likely be different in size and shape from motors produced today. In particular, the designs produced in DOE's engineering analysis exhibit longer stack length to increase efficiency. DOE also projects that the standards may result in significant increases in market share for CSCR motors (which have an extra external capacitor). DOE understands that these changes may result in the need for some OEMs who incorporate these motors to redesign their products. Nationally, about 2.5% of U.S. gross domestic product is spent on research and development (R&D; National Science Board. 2010. Science and Engineering Indicators 2010. Arlington, VA: National Science Foundation (NSB 10-01)). DOE estimates that R&D by equipment OEMs, including the design of new products, generally represents approximately 2 percent of company revenue. This percentage is slightly less than the national average to account for high technology companies that generally spend a much larger fraction of revenue on R&D than OEMs of equipment that incorporate small motors. DOE accounted for the additional costs to redesign products and incorporate differently-shaped motors by adding 2% to the OEM markup, increasing the baseline OEM markup from 1.37 to 1.39 and the incremental OEM markup from 1.27 to 1.29 for OEMs without a distributor, and 1.33 to 1.35 for OEMs that purchase motors through distributors.
DOE used these markups, along with sales taxes, installation costs, and manufacturer selling prices (MSPs) developed in the engineering analysis, to arrive at the final installed equipment prices for baseline and higher efficiency small electric motors. As explained in the NOPR (74 FR 61434), DOE defined three distribution channels for small electric motors to describe how the equipment passes from the manufacturer to the customer. DOE retained the same distribution channel market shares described in the NOPR.
Table IV.11 summarizes for each of the three identified distribution channels the baseline and incremental markups at each stage and the overall markups, including sales taxes. Weighting the markups in each channel by its share of shipments yields an average overall baseline markup of 2.52 and an average overall incremental markup of 1.86. DOE used these markups for all three types of motors.
Table IV.11—Summary of Small Electric Motor Distribution Channel Markups
Direct to OEMs
65%
Baseline
Incremental
Via distributors to OEMs
30%
Baseline
Incremental
Via distributors to end-users
5%
Baseline
Incremental
Wholesale Distributor
1.28
1.10
1.28
1.10
OEM
1.39
1.29
1.39
1.35
Retail and Post-OEM Distributor
1.43
1.18
1.43
1.18
1.44
1.18
Contractor or Installer
1.10
1.10
1.10
1.10
1.10
1.10
Sales Tax
1.0684
1.0684
1.0684
Overall
2.34
1.79
2.99
2.06
2.17
1.53
Using these markups, DOE generated motor end-user prices for each efficiency level it considered, assuming that each level represents a new minimum efficiency standard. Because it generated a range of price estimates,
DOE describes prices within a range of uncertainty.
Chapter 7 of the TSD provides additional detail on the markups analysis.
E. Energy Use Characterization
The energy use characterization estimates the annual energy consumption of small electric motors. This estimate is used in the subsequent LCC and PBP analyses (chapter 8 of the TSD) and National Impacts Analysis (NIA) (chapter 11 of the TSD). DOE determined the annual energy consumption of small electric motors by multiplying the energy use while in operation by the annual hours of operation. The energy use in operation is a function of the motor loading and the losses resulting from motor operation, based on the motor designs characterized in the engineering analysis. DOE's motor designs are also characterized by their power factor, which allows DOE to estimate the reactive power requirements of each analyzed motor.
1. Applications
DOE's shipments analysis indicates that small electric motors are used in five application categories: Pumps; fans and blowers; air compressors; conveyors and material handling; and general industrial or miscellaneous applications. Motor energy use depends on application because different applications have different annual hours of operation and different average motor loading.
In the NOPR, DOE presented the results of an analysis of motor shipments into the five application categories. Table IV.12 shows the distribution of motor shipments by application presented in the NOPR.
Table IV.12—Distribution of Motors by Application and Motor Type
Motor application
Polyphase
(%)
CSIR
(%)
CSCR
(%)
Reference Case:
Air and gas compressors
17.3
14.9
14.9
Conveyors & packaging equipment
13.3
11.9
11.9
General industrial machinery
11.3
12.5
12.5
Indus. and comm. fans and blowers
7.3
6.9
6.9
Pumps and pumping equipment
50.7
53.7
53.7
Service industry
0.0
0.0
0.0
Total
100.0
100.0
100.0
Sensitivity (NEMA Survey):
Air and gas compressors
45
22
45
Conveyors & packaging equipment
5
2
2
General industrial machinery
7
1
1
Indus. and comm. fans and blowers
23
51
29
Pumps and pumping equipment
15
13
12
Service industry
5
11
11
Total
100.0
100.0
100.0
In written comments, NEMA submitted the results of a survey of their OEM customers for motors which NEMA considers to be covered products. (NEMA, No. 24 at pp. 19 to 21) The survey reports distributions by application and owner type, estimates of annual hours of operation, and the fraction of motors that are space-constrained. NEMA also provided information on a sixth application not included in DOE's NOPR, service industry motors. The distribution by application and motor type provided by NEMA is also shown in Table IV.13.
DOE has concerns about the accuracy of the results of this survey. It is not clear which OEMs were contacted for the survey, how many responded, how representative the respondents are of the small motor market, and what specific questions were asked. It is also not clear that the survey results represent an accurate picture of the entire U.S. market for small motors, or how all OEMs will respond to today's rule. In contrast, the distributions by motor application that DOE used in the NOPR were based on analysis conducted in the early stages of the rulemaking, supplemented by a review of U.S. Census and U.S. Customs data regarding production and imports of motors and equipment containing motors. For these reasons, DOE retained its assumptions regarding the distribution of motors by application and sector; however, DOE did run a sensitivity case that reflects the results of the NEMA survey. This sensitivity is discussed in Section VI, and the detailed results are presented in the TSD.
Table IV.13 shows the distributions of motors by sector within each application used in the NOPR, as well as the results provided by the NEMA survey.
Table IV.13—Distribution of Motors by Application and Sector
Application
Sector
Industrial
(%)
Commercial
(%)
Agricultural
(%)
Residential
(%)
Total
(%)
Reference Case:
Air and gas compressors
40
40
10
10
100
Conveyors & Packaging Equipment
40
50
10
0
100
General industrial machinery
50
40
10
0
100
Indus. and comm. fans and blowers
50
50
0
0
100
Pumps and pumping equipment
40
35
20
5
100
Service industry
0
0
0
0
N/A
Sensitivity (NEMA Survey):
Air and gas compressors
0
15
15
70
100
Conveyors & Packaging Equipment
65
35
0
0
100
General industrial machinery
80
20
0
0
100
Indus. and comm. fans and blowers
20
80
0
0
100
Pumps and pumping equipment
10
40
20
30
100
Service industry
10
80
0
10
100
2. Annual Hours of Operation and Motor Loading
In the NOPR, and in today's final rule, DOE characterized the motor loading and annual hours of operation with distributions for each analyzed motor application. DOE's estimates of the average motor loading in each application are unchanged from the NOPR to today's final rule. Table IV.14 shows the average loading in each application. DOE assume
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