# Energy Conservation Program: Test Procedures for Electric Motors

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2013-15132

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** June 26, 2013
- **Citation:** 78 FR 38456

## Text

DEPARTMENT OF ENERGY
10 CFR Part 431
[Docket No. EERE-2012-BT-TP-0043]
RIN 1904-AC89
Energy Conservation Program: Test Procedures for Electric Motors

AGENCY:

Office of Energy Efficiency and Renewable Energy, Department of Energy.

ACTION:

Notice of proposed rulemaking.

SUMMARY:

This notice proposes to clarify aspects of certain U.S. Department of Energy (DOE) energy efficiency regulations related to electric motors. DOE is considering establishing definitions, specifying testing set-up procedures necessary to test, and extending DOE's existing test procedures for electric motors to certain electric motor types that have not been regulated by DOE. These actions are being proposed to clarify the scope of regulatory coverage for electric motors and to ensure accurate and consistent measurements when determining the energy efficiency of various types of electric motors. This notice seeks comment on this proposal and requests comments, data, and other information to assist DOE in deciding whether to finalize or modify these provisions.

DATES:

DOE will hold a public meeting on Tuesday, July 16, 2013, from 9 a.m. to 4 p.m., in Washington, DC. The meeting will also be broadcast as a webinar. See section V, “Public Participation,” for webinar registration information, participant instructions, and information about the capabilities available to webinar participants.

DOE will accept comments, data, and information regarding this NOPR before and after the public meeting, but no later than September 9, 2013. See section V, “Public Participation.” for details.

ADDRESSES:

The public meeting will be held at the U.S. Department of Energy, Forrestal Building, Room 8E-089, 1000 Independence Avenue SW., Washington, DC 20585. To attend, please notify Ms. Brenda Edwards at (202) 586-2945. For detailed information regarding attendance and participation at the public meeting, see section V, “Public Participation.”

Any comments submitted must identify the NOPR for Test Procedures for Electric Motors, and provide docket number EERE-2012-BT-TP-0043 and/or regulation identifier number (RIN) number 1904-AC89. Comments may be submitted using any of the following methods:

1.
Federal eRulemaking Portal:

http://www.regulations.gov.
Follow the instructions for submitting comments.

2.
Email:

ElectricMotors2012TP0043@ee.doe.gov.
Include the docket number EERE-2012-BT-TP-0043 and/or RIN 1904-AC89 in the subject line of the message.

3.
Mail:
Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Program, Mailstop EE-2J, 1000 Independence Avenue SW., Washington, DC 20585-0121. If possible, please submit all items on a compact disc. It is not necessary to include printed copies.

4.
Hand Delivery/Courier:
Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Program, 6th Floor, 950 L'Enfant Plaza SW., Washington, DC 20024. Telephone: (202) 586-2945. Please submit one signed paper original.

For detailed instructions on submitting comments and additional information on the rulemaking process, see section V, “Public Participation.”

Docket:
The docket is available for review at
www.regulations.gov,
including
Federal Register
notices, public meeting attendee lists and transcripts, comments, and other supporting documents/materials.

A link to the docket Web page can be found at:
http://www1.eere.energy.gov/buildings/appliance_standards/rulemaking.aspx/ruleid/74.

For further information on how to submit a comment, review other public comments and the docket, or participate in the public meeting, contact Ms. Brenda Edwards at (202) 586-2945 or by email:
Brenda.Edwards@ee.doe.gov.

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. Email
:

medium_electric_motors@ee.doe.gov

Ms. Ami Grace-Tardy, U.S. Department of Energy, Office of the General Counsel, GC-71, 1000 Independence Avenue SW., Washington, DC 20585. Telephone: (202) 586-5709. Email:
Ami.Grace-Tardy@hq.doe.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

A. Authority

B. Background

II. Summary of Notice of Proposed Rulemaking

III. Discussion

A. Proposed Effective Dates for the Amended Test Procedures

B. Expanding the Scope of Coverage of Energy Conservation Standards

C. Motor Type Definitions

1. National Electrical Manufacturers Association Design A and Design C Motors

2. International Electrotechnical Commission Designs N and H Motors

3. Electric Motors with Sealed and Moisture Resistant Windings

4. Inverter-Capable Electric Motors

5. Totally Enclosed Non-Ventilated Electric Motors

D. Electric Motor Types Requiring Definitions and Test Procedure Instructions

1. Immersible Electric Motors and Electric Motors with Contact Seals

2. Integral and Non-Integral Brake Electric Motors

3. Partial Electric Motors

E. Electric Motor Types Requiring Only Test Procedure Instructions

1. Electric Motors with Non-Standard Endshields or Flanges

2. Close-Coupled Pump Electric Motors and Electric Motors with Single or Double Shaft Extensions of Non-Standard Dimensions or Additions

3. Vertical Electric Motors

4. Electric Motor Bearings

F. General Clarification for Certain Electric Motor Types

1. Electric Motors with Non-Standard Bases, Feet or Mounting Configurations

G. Electric Motor Types DOE Proposes Not to Regulate at This Time

1. Air-Over Electric Motor

2. Component Set of an Electric Motor

3. Liquid-Cooled Electric Motor

4. Submersible Electric Motor

5. Definite-Purpose Inverter-Fed Electric Motors

IV. 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 of 1995

D. Review Under the National Environmental Policy Act of 1969

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 Treasury and General Government Appropriations Act, 2001

K. Review Under Executive Order 13211

L. Review Under Section 32 of the Federal Energy Administration Act of 1974

V. Public Participation

a. Attendance at Public Meeting

b. Procedure for Submitting Prepared General Statements for Distribution

c. Conduct of Public Meeting

d. Submission of Comments

e. Issues on Which DOE Seeks Comment

VI. Approval of the Office of the Secretary

I. Introduction

A. Authority

Title III of the Energy Policy and Conservation Act, 42 U.S.C. 6291,

et

seq.,

(“EPCA” or “the Act”) sets forth a variety of provisions designed to improve the energy efficiency of products and commercial equipment. (All references to EPCA refer to the statute as amended through the American Energy Manufacturing Technical Corrections Act (AEMTCA 2012), Public Law 112-210 (December 18, 2012)). Part C of Title III (42 U.S.C. 6311-6317), which was subsequently redesignated as Part A-1 for editorial reasons, establishes an energy conservation program for certain industrial equipment, which includes electric motors, the subject of today's notice. (42 U.S.C. 6311(1)(A), 6313(b))

B. Background

In the Energy Policy Act of 1992, Public Law 102-486 (October 24, 1992) (EPACT 1992), Congress amended EPCA to establish energy conservation standards, test procedures, compliance certification, and labeling requirements for certain electric motors. (When used in context, the term “motor” refers to “electric motor” in this document.) On October 5, 1999, DOE published in the
Federal Register
, a final rule to implement these requirements. 64 FR 54114. In 2007, section 313 of the Energy Independence and Security Act (EISA 2007) amended EPCA by: (1) Striking the definition of “electric motor,” (2) setting forth definitions for “general purpose electric motor (subtype I)” and “general purpose electric motor (subtype II),” and (3) prescribing energy conservation standards for “general purpose electric motors (subtype I),” “general purpose electric motors (subtype II), “fire pump electric motors,” and “NEMA Design B general purpose electric motors” with a power rating of more than 200 horsepower but not greater than 500 horsepower. (42 U.S.C. 6311(13), 6313(b)). Consequently, on March 23, 2009, DOE updated the corresponding regulations at 10 CFR part 431 with the new definitions and energy conservation standards. 74 FR 12058. On December 22, 2008, DOE proposed to update the test procedures under 10 CFR part 431 both for electric motors and small electric motors. 73 FR 78220. DOE finalized key provisions related to small electric motor testing in a 2009 final rule at 74 FR 32059 (July 7, 2009), and further updated test procedures for electric motors and small electric motors at 77 FR 26608 (May 4, 2012).

Today's notice of proposed rulemaking (NOPR) focuses on electric motors and proposes to add the aforementioned definitions and additional testing set-up instructions and clarifications to the current test procedures under subpart B of 10 CFR part 431 for a wider variety of electric motor types than currently regulated. Additionally, DOE is proposing to extend the applicability of DOE's existing electric motor test procedure in 10 CFR part 431 to the wider scope of currently unregulated motors. DOE is proposing such amendments because the additional testing set-up instructions and clarifications are designed to help manufacturers of certain types of motors prepare them for testing under the applicable test procedure. The proposed steps are intended to enable a manufacturer to consistently measure the losses and determine the efficiency of a wider variety of motors, and potentially facilitate the application of energy conservation standards to a wider array of motors than what is currently covered under 10 CFR part 431.
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In addition, DOE is considering prescribing standards for some electric motors addressed in this notice through a parallel energy conservation standards-related activity. See 77 FR 43015 (July 23, 2012). To ensure consistency between the two rulemakings, this test procedure NOPR addresses scope of coverage and test procedure issues raised in response to DOE's current electric motors energy conservation standards rulemaking. See 76 FR 17577 (March 30, 2011); 77 FR 43015 (July 23, 2012). Finally, to provide regulatory clarity and consistency with existing regulations, today's proposed rule also defines NEMA Design A motors, NEMA Design C motors, International Electrotechnical Commission (IEC) Design H motors and IEC Design N motors, which are covered under subpart B of 10 CFR part 431.

1
EPCA, as amended by EPACT 1992, had previously defined an “electric motor” as any motor which is a general purpose T-frame, single-speed, foot-mounting, polyphase squirrel-cage induction motor of the National Electrical Manufacturers Association, Design A and B, continuous rated, operating on 230/460 volts and constant 60 Hertz line power as defined in NEMA Standards Publication MG1-1987. (42 U.S.C. 6311(13)(A) (1992)) Through subsequent amendments to EPCA made by EISA 2007, Congress removed this definition and added language denoting two new subtypes of general purpose electric motors. (See 42 U.S.C. 6311(13)(A)-(B) (2012)).

By way of background, DOE notes that section 343(a)(5)(A) of EPCA, 42 U.S.C. 6314(a)(5)(A), initially required that the test procedures to determine electric motor efficiency shall be those procedures specified in two documents: National Electrical Manufacturers Association (NEMA) Standards Publication MG1-1987
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and Institute of Electrical and Electronics Engineers (IEEE) Standard 112 Test Method B for motor efficiency, as in effect on the date of enactment of EPACT 1992. Section 343(a)(5)(B)-(C) of EPCA, 42 U.S.C. 6314(a)(5)(B)-(C), provides in part that if the NEMA- and IEEE-developed test procedures are amended, the Secretary of Energy shall so amend the test procedures under 10 CFR part 431, unless the Secretary determines, by rule, that the amended industry procedures would not meet the requirements for test procedures to produce results that reflect energy efficiency, energy use, and estimated operating costs of the tested motor, or would be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)-(3), (a)(5)(B)) Subsequently, as newer versions of the NEMA and IEEE test procedures for electric motors were published and used by industry, DOE updated 10 CFR part 431. For example, see 64 FR 54114 (October 5, 1999) that incorporated by reference into 10 CFR part 431 applicable provisions of NEMA Standards Publication MG1-1993 and IEEE Standard 112-1996, and codified them at 10 CFR 431.16 and appendix B to subpart B of 10 CFR part 431. DOE also added the equivalent test procedure—Canadian Standards Association (CSA) CAN/CSA C390-93, “Energy Efficiency Test Methods for Three-Phase Induction Motors,” because NEMA added this procedure to its Standards Publication, MG1, when it was revised and updated in 1993. See 61 FR 60440, 60446 (November 27, 1996).

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NEMA MG1 does not contain the actual methods and calculations needed to perform an energy efficiency test but, rather, refers the reader to the proper industry methodologies in IEEE Standard 112 and CSA C390-10.

On May 4, 2012, DOE incorporated by reference the updated versions of the above test procedures: NEMA MG1-2009, IEEE 112-2004, and CAN/CSA C390-10. 77 FR 26608, 26638 (the “2012 final test procedure.”) DOE made these updates to ensure consistency between 10 CFR part 431 and current industry procedures and related practices. Since publication of the 2012 final test procedure, NEMA Standards Publication MG1 has been updated to MG1-2011. The text of the sections and paragraphs of NEMA MG1-2009, which is incorporated by reference under 10 CFR part 431.15, is identical to the text of the relevant sections and paragraphs of NEMA MG1-2011. The substance of those NEMA MG1-2009 sections and paragraphs incorporated by reference into subpart B of 10 CFR part 431 were subjected to public notice and comment during the 2012 test procedure rulemaking. DOE addressed its reasons for incorporating the MG1-2009 text into its regulations in its May 2012 final

rule. See 77 FR at 26616-26617. For all the above reasons, DOE has preliminarily chosen not to update its regulations with NEMA MG1-2011, but is accepting public comment on this preliminary decision.

II. Summary of Notice of Proposed Rulemaking

In this NOPR, DOE proposes to:

(1) Define a variety of electric motor configurations (i.e., types) that are currently covered under 10 CFR 431.25 but are not currently defined under 10 CFR 431.12;

(2) Define a variety of electric motor configurations (i.e., types) that are not currently covered under 10 CFR 431.25 and are not currently defined under 10 CFR 431.12; and

(3) Clarify the necessary testing “set-up” procedures to facilitate the testing of the currently not covered motor types under IEEE Standard 112 (Test Method B) or CSA Standard C390-10.

Today's NOPR was precipitated by DOE's ongoing electric motors standards rulemaking. DOE published its “Framework Document for Commercial and Industrial Electric Motors” (the “2010 framework document”) (75 FR 59657) on September 28, 2010. Public comments filed in response urged DOE to consider regulating the efficiency of certain definite and special purpose motors. DOE, in turn, published a request for information regarding definite and special purpose motors (the “March 2011 RFI”). See 76 FR 17577 (March 30, 2011). DOE is considering whether to propose expanding the scope of what its electric motor standards regulate to include all continuous duty, single speed, squirrel-cage, polyphase alternating-current, induction motors, with some narrowly defined exemptions. See 77 FR 43015 (July 23, 2012). Today's NOPR addresses and solicits comment on test procedure issues arising from potentially expanding the scope of DOE's energy efficiency requirements to include certain motor types that are not currently required to meet energy conservation standards. In particular, today's proposal includes definitions for those motor types that DOE may consider regulating and those types that DOE is not considering regulating at this time. DOE is coordinating today's NOPR with a parallel electric motor energy conservation standards rulemaking. To the extent possible, DOE will consider all comments submitted in response to the electric motors test procedure or standards rulemaking in connection with both activities.

In addition to proposing to include new definitions, today's notice proposes to add certain steps to the applicable test procedures contained in appendix B to subpart B of 10 CFR part 431, to accommodate setting those motors up for testing that DOE is considering regulating. Because the proposed amendments are strictly limited to those steps necessary to facilitate testing under the currently incorporated test procedures, DOE does not anticipate that the proposal would affect the actual measurement of losses and the subsequent determination of efficiency for any of the electric motors within the scope of today's proposed rulemaking.

The proposed revisions are summarized in the table below and addressed in detail in the following sections. Note that all citations to various sections of 10 CFR part 431 throughout this preamble refer to the current version of 10 CFR part 431. The proposed regulatory text follows the preamble to this notice. DOE seeks comments from interested parties on each of the proposed revisions.

Table II-1—Summary of Changes Proposed in This NOPR and Affected Sections of 10 CFR Part 431

Existing section in 10 CFR part 431
Summary of proposed modifications

Section 431.12—Definitions
• Adds new definitions for:

○ Air-over electric motor.

○ Component set.

○ Definite-purpose inverter-fed electric motor.

○ Electric motor with moisture resistant windings.

○ Electric motor with sealed windings.

○ IEC Design H motor.

○ IEC Design N motor.

○ Immersible electric motor.

○ Integral brake electric motor.

○ Inverter-capable electric motor.

○ Liquid-cooled electric motor.

○ NEMA Design A motor.

○ NEMA Design C motor.

○ Non-integral brake electrical motor.

○ Partial electric motor.

○ Submersible electric motor.

○ Totally enclosed non-ventilated (TENV) electric motor.

Appendix B to Subpart B—Uniform Test Method for Measuring Nominal Full Load Efficiency of Electric Motors

• Updates test procedure set-up methods for:
○ Close-coupled pump electric motors and electric motors with single or double shaft extensions of non-standard dimensions or additions.

○ Electric motors with non-standard endshields or flanges.

○ Immersible electric motors and electric motors with contact seals.

○ Integral brake electric motors.

○ Non-integral brake electric motors.

○ Partial electric motors.

○ Vertical electric motors and electric motors with bearings incapable of horizontal operation.

○ Close-coupled pump electric motors.

DOE developed today's proposal after considering public input, including written comments, from a wide variety of interested parties. All commenters, along with their corresponding abbreviations and affiliation, are listed in Table II.2 below. The issues raised by these commenters are addressed in the discussions that follow.
3

3
As comments have not yet been submitted for this test procedure rulemaking, all comments cited in this NOPR can be found in the Electric Motors Standards rulemaking docket with the number EERE-2010-BT-STD-0027.

Table II-2—Summary of NOPR Commenters

Company or organization
Abbreviation
Affiliation

Appliance Standards Awareness Project
ASAP
Energy Efficiency Advocate.

Baldor Electric Co.
Baldor
Manufacturer.

Copper Development Association
CDA
Trade Association.

Motor Coalition *
MC
Energy Efficiency Advocates, Trade Associations, Manufacturers.

National Electrical Manufacturers Association
NEMA
Trade Association.

* The members of the Motor Coalition include: National Electrical Manufacturers Association, American Council for an Energy-Efficient Economy, Appliance Standards Awareness Project, Alliance to Save Energy, Earthjustice, Natural Resources Defense Council, Northwest Energy Efficiency Alliance, Northeast Energy Efficiency Partnerships, and Northwest Power and Conservation Council.

III. Discussion

A.
Proposed Effective Dates for the Amended Test Procedures

If adopted, the proposed amendments would become effective 30 days after the publication of the final rule. As previously explained, today's proposal would primarily add a new section to DOE's test procedure with the steps that the manufacturers of certain types of special and definite purpose electric motors would need to take before testing a motor. Because these test procedure changes would add only a new section to the existing test procedure for motor types that are not currently regulated (i.e., special and definite purpose motors), manufacturers of motors currently covered by DOE regulations (i.e., general purpose electric motors (subtype I and subtype II), including fire pump electric motors and NEMA Design B motors with a power rating of more than 200 horsepower but not greater than 500 horsepower) can continue to use the current test procedure until 180 days after publication of the final rule. At 180 days after publication of the final rule, both manufacturers of currently regulated motors and manufacturers of special and definite purpose motors for which definitions or testing set-up procedures are proposed in this rule may not make any representations regarding energy use or the cost of energy use for all electric motors addressed in today's rulemaking unless such representations are based on the results of testing, or calculations from a substantiated alternative efficiency determination method (AEDM), that reflect values of efficiency that would be obtained through testing in accordance with the amended test procedures. In addition, 180 days after publication of the final rule, both manufacturers of currently regulated motors and manufacturers of special and definite purpose motors for which definitions or testing set-up procedures are provided would be required to comply with and use the amended test procedures to determine if the covered electric motor types they manufacture comply with the applicable energy conservation standards.
4

See 42 U.S.C. 6314(d).

4
DOE acknowledges that there are no current energy conservation standards for the majority of the motor types covered in today's proposed rule. If DOE establishes standards for these motor types, manufacturers will be required to use the proposed test procedure to certify compliance with these standards.

B. Expanding the Scope of Coverage of Energy Conservation Standards

DOE has the authority to set energy conservation standards for a wider range of electric motors than those classified as general purpose electric motors (e.g., definite or special purpose motors). The EPACT 1992 amendments to EPCA had defined “electric motor” to include a certain type of “general purpose” motor that Congress would eventually classify as a general purpose electric motor (subtype I). (42 U.S.C. 6311(13)(A) (1992)) Those amendments also defined several other types of motors, including definite purpose motors and special purpose motors. (See 42 U.S.C. 6311(13)(C) and (D) (1992)) EPACT 1992 set energy conservation standards for “electric motors” (i.e., general purpose electric motors (subtype I)) and explicitly stated that the standards did not apply to definite purpose or special purpose motors.
5

(42 U.S.C. 6313(b)(1)) (1992)) EISA 2007 struck the narrow EPACT 1992 definition for “electric motor” and replaced it with the heading “Electric motors.” As a result of these changes, both definite and special purpose motors fell under the broad heading of “Electric motors” that previously only applied to “general purpose” motors. While EISA 2007 set specific standards for general purpose electric motors, it did not explicitly apply these new requirements to definite or special purpose motors. (See generally 42 U.S.C. 6313(b) (2012))

5
For the most part, DOE understands that a fire pump electric motor is a NEMA Design B motor, except it does not have a thermal limit switch that would otherwise preclude multiple starts. In other words, a NEMA Design B electric motor has a thermal limit switch that protects the motor, whereas a fire pump electric motor does not have such a thermal limit switch to ensure that the motor will start and operate to pump water to extinguish a fire.

Although DOE believes that EPCA, as amended through EISA 2007, provides sufficient statutory authority for the regulation of special purpose and definite purpose motors as “electric motors,” DOE notes it has additional authority provided under section 10 of AEMTCA (to be codified at 42 U.S.C. 6311(2)(B)) to generally regulate “other motors” as covered “industrial equipment.” Therefore, even if special and definite purpose motors were not “electric motors,” special and definite purpose motors would be considered as “other motors” that EPCA already treats as covered industrial equipment.
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6
EPCA specifies the types of industrial equipment that can be classified as covered in addition to the equipment enumerated in 42 U.S.C. 6311(1). This equipment includes “other motors” (to be codified at 42 U.S.C. 6311(2)(B)). Industrial equipment must also, without regard to whether such equipment is in fact distributed in commerce for industrial or commercial use, be of a type that: (1) In operation consumes, or is designed to consume, energy in operation; (2) to any significant extent, is distributed in commerce for industrial or commercial use; and (3) is not a covered product as defined in 42 U.S.C. 6291(a)(2) of EPCA, other than a component of a covered product with respect to which there is in effect a determination under 42 U.S.C. 6312(c). (42 U.S.C. 6311 (2)(A)). Data from the 2002 United States Industrial Electric Motor Systems Market Opportunities Assessment estimated total energy use from industrial motor systems to be 747 billion kWh. Based on the expansion of industrial activity, it is likely that current annual electric motor energy use is higher than this figure. Electric motors are distributed in commerce for both the industrial and commercial

sectors. According to data provided by the Motors Coalition, the number of electric motors manufactured in, or imported into, the United States is over five million electric motors annually, including special and definite purpose motors. Finally, special and definite purpose motors are not currently regulated under Title 10 of the Code of Federal Regulations, part 430 (10 CFR part 430).

To classify equipment as covered commercial or industrial equipment, the Secretary must also determine that classifying the equipment as covered equipment is necessary for the purposes of Part A-1 of EPCA. The purpose of Part A-1 is to improve the efficiency of electric motors, pumps and certain other industrial equipment to conserve the energy resources of the nation. (42 U.S.C. 6312(a)-(b)) In today's proposal, DOE has tentatively determined that the regulation of special and definite purpose motors is necessary to carry out the purposes of part A-1 of EPCA because regulating these motors will promote the conservation of energy supplies. Efficiency standards that may result from coverage would help to capture some portion of the potential for improving the efficiency of special and definite purpose motors.

Consistent with the changes made by EISA 2007, DOE defined the term “electric motor” broadly. See 77 FR 26633 (May 4, 2012). That definition covers “general purpose,” “special purpose” and “definite purpose” electric motors (as defined by EPCA). Previously, EPCA did not require either “special purpose” or “definite purpose” motor types to meet energy conservation standards because they were not considered “general purpose” under the EPCA definition of “general purpose motor”—a necessary element to meet the pre-EISA 2007 “electric motor” definition. See 77 FR 26612. Because of the restrictive nature of the prior electric motor definition, along with the restrictive definition of the term “industrial equipment,” DOE would have been unable to set standards for such motors. (See 42 U.S.C. 6311(2)(B) (limiting the scope of equipment covered under EPCA)) In view of the changes introduced by EISA 2007 and the absence of current Federal energy conservation standards for special purpose and definite purpose motors, as noted in chapter 2 of DOE's July 2012 electric motors preliminary analysis technical support document (TSD),
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it is DOE's view that both are categories of “electric motors” covered under EPCA, as currently amended. Accordingly, DOE is considering establishing standards for certain definite purpose and special purpose motors in the context of a separate rulemaking. At this time, DOE is considering setting energy conservation standards for only those motors that exhibit all of the following nine characteristics:

7
The preliminary TSD published in July 2012 is available at:
http://www.regulations.gov/#!documentDetail;D=EERE-2010-BT-STD-0027-0023

• Is a single-speed, induction motor,

• Is rated for continuous duty (MG1) operation or for duty type S1 (IEC),

• Contains a squirrel-cage (MG1) or cage (IEC) rotor,

• Operates on polyphase alternating current 60-hertz sinusoidal line power,

• Is rated 600 volts or less,

• Has a 2-, 4-, 6-, or 8-pole configuration,

• Has a three-digit NEMA frame size (or IEC metric equivalent) or an enclosed 56 NEMA frame size (or IEC metric equivalent),

• Is rated no more than 500 horsepower, but greater than or equal to 1 horsepower (or kilowatt equivalent), and

• Meets all of the performance requirements of one of the following motor types: a NEMA Design A, B, or C motor or an IEC design N or H motor.

Motor types that exhibit all of the characteristics listed above, but that DOE is declining to subject to energy conservation standards at this time because of the inability to test them for efficiency in a repeatable manner, would be identified by DOE through a parallel notice of proposed rulemaking. To prepare this test procedure NOPR, DOE has incorporated feedback received during the August 21, 2012, electric motors standards preliminary analysis public meeting, comments on the March 2011 RFI, and comments on the July 2012 electric motors preliminary analysis (“electric motors preliminary analysis”) as well as information gleaned from discussions with testing laboratories, manufacturers, and subject matter experts (SMEs).

To facilitate the potential application of energy conservation standards to motors built in the configurations described above, DOE proposes to first define the motors and then provide additional testing instructions to enable them to be tested using the existing DOE test method for electric motors. The definitions under consideration would address motors currently subject to standards, certain motors DOE is considering requiring to meet standards, and certain other motors that DOE is, at this time, considering not regulating through energy conservation standards. Some clarifying definitions, such as the definitions for NEMA Design A and NEMA Design C motors from NEMA MG1-2009, would be added. However, DOE understands that some motors, such as partial motors and integral brake motors, do not have standard, industry-accepted definitions. For such motor types, DOE conducted its own independent research and consulted with SMEs, manufacturers, and the Motor Coalition so that DOE could create the working definitions that are proposed in section III of this NOPR. For the definitions of
“electric motor with moisture resistant windings” and “electric motor with sealed windings,”
which reference certain subsections of NEMA MG1-2009, DOE intends to incorporate by reference the cited sections of NEMA MG1-2009.

DOE believes that the existing IEEE Standard 112 (Test Method B) and CSA C390-10 test procedures can be used to accurately measure losses and determine the energy efficiency for this additional group (or “expanded scope”) of motors because all of the motor types under consideration are single-speed, polyphase induction motors with electromechanical characteristics similar to those currently subject to energy conservation standards. While some of these motor types require the addition of testing step-up instructions prior to testing, all can be tested using the same methodology provided in those industry-based procedures DOE has already incorporated into its regulations.

Testing an electric motor using IEEE Standard 112 (Test Method B) or CSA C390-10 requires some basic electrical connections and physical configurations. To test an electric motor under either procedure, the electric motor is first mounted on a test bench in a horizontal position. This means that the motor shaft is horizontal to the test bench and the motor is equipped with antifriction bearings that can withstand operation while in a horizontal position.
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Instruments are then connected to the power leads of the motor to measure input power, voltage, current, speed, torque, temperature, and other input, output, and performance characteristics. Thermocouples are attached to the motor to facilitate temperature measurement. Stator winding resistance is measured while the motor is at ambient, or room, temperature. No-load measurements are recorded while the motor is operating, both temperature and input power have stabilized, and the shaft extension is free from any attachments. After ambient temperature and no-load measurements are taken, a dynamometer is attached to the motor shaft to take “loaded” measurements. A dynamometer is a device that simultaneously applies and measures torque for a motor. The dynamometer applies incremental loads to the shaft, typically at 25, 50, 75, 100, 125, and 150 percent of the motor's total rated output horsepower. This allows the testing laboratory to record motor performance

criteria, such as power output and torque, at each incremental load point. Additional stator winding resistance measurements are taken to record the temperature at the different load points.

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DOE is aware of some types of bearings that cannot operate while the motor is in a horizontal position. DOE addresses such bearings in later sections of this NOPR.

DOE believes that clarifying instructions may be necessary to test some of the expanded-scope motors that DOE is considering and for which DOE is conducting an energy conservation standards rulemaking because some motors may require modifications before they can operate continuously and be tested on a dynamometer in a manner consistent with the current DOE test procedure. For example, a partial electric motor may be engineered for use without one or both endshields, including bearings, because it relies on mechanical support from another piece of equipment. Without these components, the motor would be unable to operate as a stand-alone piece of equipment. Therefore, DOE is proposing to add instructions to facilitate consistent and repeatable procedures for motors such as these. These additions were based on testing and research conducted by the Department along with technical consultations with SMEs, manufacturers, testing laboratories, and various trade associations. Table III-1 lists those electric motors that are covered under current energy conservation standards or that DOE is analyzing for potential new energy conservation standards. In each case, the table identifies whether DOE is proposing to address a given motor through the use of new definitions, test procedure instructions, or both.

Table III-1—Motor Types Considered for Regulation in DOE Proposed Test Procedure and Standards Rulemakings

Motor type

Currently
subject to
standards?

Under
consideration
for potential
standards?

New definition
proposed?

Additional
set-up
instructions
proposed?

NEMA Design A Motors
Yes
Yes
Yes
No.

NEMA Design C Motors
Yes
Yes
Yes
No.

IEC Design N Motors
Yes
Yes
Yes
No.

IEC Design H Motors
Yes
Yes
Yes
No.

Electric Motors with Moisture Resistant or Sealed Windings
No
Yes
Yes
No.

Inverter-Capable Electric Motors
Yes
Yes
Yes
No.

Totally Enclosed Non-Ventilated Electric Motors
No
Yes
Yes
No.

Immersible Electric Motors
No
Yes
Yes
Yes.

Electric Motors with Contact Seals
Yes
Yes
No
Yes.

Integral Brake Electric Motors
No
Yes
Yes
Yes.

Non-Integral Brake Electric Motors
Yes
Yes
Yes
Yes.

Partial Electric Motors
No
Yes
Yes
Yes.

Electric Motors with Non-Standard Endshields or Flanges
No
Yes
No
Yes.

Close-Coupled Pump Electric Motors
Yes
Yes
No
Yes.

Electric Motors with Special Shafts
No
Yes
No
Yes.

Vertical Solid Shaft Motors
Yes
Yes
No
Yes.

Vertical Hollow-Shaft Motors
No
Yes
No
Yes.

Electric Motors with Thrust Bearings
No
Yes
No
Yes.

Electric Motors with Sealed Bearings
Yes
Yes
No
Yes.

Electric Motors with Roller Bearings
No
Yes
No
Yes.

Electric Motors with Sleeve Bearings
Yes
Yes
No
Yes.

Electric Motors with Non-Standard Bases
No
Yes
No
No.

Air-Over Electric Motors
No
No
Yes
No.

Component Sets
No
No
Yes
No.

Liquid-cooled Electric Motors
No
No
Yes
No.

Submersible Electric Motors
No
No
Yes
No.

Definite-Purpose Inverter-Fed Electric Motors
No
No
Yes
No.

C. Motor Type Definitions

During the course of the 2012 final test procedure rulemaking, some interested parties questioned why DOE defined NEMA Design B motors but not NEMA Design A or Design C motors. DOE explained that it chose to adopt a definition for “NEMA Design B” motor because the application section in MG1 (MG1-1.19.1.2 in both MG1-2009 and MG1-2011) contained a typographical error that required correcting for purposes of DOE's regulations. DOE also noted that it may incorporate a corrected version of the “NEMA Design C” motor definition in a future rulemaking—that definition, which is found in MG1-1.19.1.3, also contains a typographical error. DOE did not intend to add definitions for NEMA Design A and IEC Design N, as the existing definitions found in MG1 are correct as published. 77 FR 26616, 26634 (May 4, 2012). In view of DOE's intention to consider regulating other types of motors, DOE now believes it is necessary to make clear the terms and definitions for them as well. DOE understands that many terms and definitions applicable to motors and used in common industry parlance for voluntary standards and day-to-day business communication are not necessarily defined with sufficient clarity for regulatory purposes. DOE does not, at this time, propose to add amendments related to such types of motors other than to provide more precise definitions for them to sufficiently capture the particular characteristics attributable to each and aid the manufacturing community in determining whether a particular basic model is covered by DOE's regulations for electric motors.

1. National Electrical Manufacturers Association Design A and Design C Motors

NEMA MG1-2009 defines the following three types of polyphase, alternating current, induction motors: NEMA Designs A, B, and C. NEMA MG1-2009 establishes the same pull-up, breakdown, and locked-rotor torque requirements for both NEMA Design A

and NEMA Design B motors.
9

However, a NEMA Design A motor must be designed such that its locked-rotor current exceeds the maximum locked-rotor current established for a NEMA Design B motor. Unless the application specifically requires the higher locked-rotor current capability offered by a NEMA Design A motor, a NEMA Design B motor (that has the same specified minimum torque characteristics as the NEMA Design A motor) is often used instead because of the additional convenience offered by these motors when compared to Design A motors. (See NEMA, EERE-2010-BT-STD-0027-0054 at 36 (noting the additional convenience offered by Design B motors over Design A motors with respect to selecting disconnecting methods and in satisfying National Electrical Code and Underwriters Laboratory requirements.)) In addition, DOE understands that NEMA Design B motors are frequently preferred because the user can easily select motor control and protection equipment that meets the applicable requirements of the National Fire Protection Association (NFPA) National Electrical Code (NFPA 70). These motors are also listed by private testing, safety, or certification organizations, such as CSA International and Underwriters Laboratory. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 36) A NEMA Design C motor requires a minimum locked-rotor torque per NEMA MG1-2009, Table 12-3, which is higher than either the NEMA Design A or Design B minimum locked-rotor torque required per NEMA MG1-2009, Table 12-2.

9

Locked-rotor torque
is the torque that a motor produces when it is at rest or zero speed and initially turned on. A higher locked-rotor torque is important for hard-to-start applications, such as positive displacement pumps or compressors. A lower locked-rotor torque can be accepted in applications such as centrifugal fans or pumps where the start load is low or close to zero.
Pull-up torque
is the torque needed to cause a load to reach its full rated speed. If a motor's pull-up torque is less than that required by its application load, the motor will overheat and eventually stall.
Breakdown torque
is the maximum torque a motor can produce without abruptly losing motor speed. High breakdown torque is necessary for applications that may undergo frequent overloading, such as a conveyor belt. Often, conveyor belts have more product or materials placed upon them than their rating allows. High breakdown torque enables the conveyor to continue operating under these conditions without causing heat damage to the motor.

In view of the above, DOE is proposing to incorporate a definition for both “NEMA Design A motor” and “NEMA Design C motor” to improve regulatory clarity. DOE notes it has already adopted a definition for “NEMA Design B motor” at 10 CFR 431.12. DOE believes that providing definitions for other motor types will provide consistency in the treatment of all considered motors. The proposed definitions for NEMA Design A and Design C motors are based on the definitions in NEMA MG1-2009, paragraphs 1.19.1.1 and 1.19.1.3, respectively. DOE believes that the NEMA MG1-2009 definition of “NEMA Design A motor” is sufficiently clear and concise and is proposing to add it with minor clarifying elements. DOE is proposing to incorporate the definition of “NEMA Design C motor” from NEMA MG1-2009, paragraph 1.19.1.3 with some minor corrections because the NEMA MG1-2009 definition appears to contain typographical errors
10

with regard to the tables referenced in the definition. As detailed in the proposed regulations below, a NEMA Design A motor is defined as a squirrel-cage motor designed to withstand full-voltage starting and developing locked-rotor torque, pull-up torque, breakdown torque, and locked-rotor current as specified in NEMA MG1-2009; and with a slip at rated load of less than 5 percent for motors with fewer than 10 poles. A NEMA Design C motor is defined as a squirrel-cage motor designed to withstand full-voltage starting and developing locked-rotor torque for high-torque applications, pull-up torque, breakdown torque, and locked-rotor current as specified in NEMA MG1-2009; and with a slip at rated load of less than 5 percent.

10
In NEMA MG1-2009, the definition for NEMA Design C refers the reader to paragraph 12.34.1 for locked-rotor current limits for 60 hertz motors. The appropriate paragraph appears to be 12.35.1.

As previously mentioned, DOE is proposing these definitions to retain consistency with other already incorporated regulatory definitions. General purpose electric motors that meet the definition of NEMA Design A and Design C motor and are rated between 1 and 200 horsepower are currently subject to energy conservation standards. DOE is not aware of any difficulties in testing either of these motor design types using the current procedures. Therefore, DOE is not proposing any test procedure amendments for these motor types at this time. DOE requests comment on its proposal to incorporate definitions for NEMA Design A and NEMA Design C motors based on the NEMA MG1-2009 definitions of these motor designs.

2. International Electrotechnical Commission Designs N and H Motors

Similar to NEMA, the European International Electrotechnical Commission (IEC) produces industry standards that contain performance requirements for electric motors. Analogous to NEMA Designs B and C, the IEC has design types N and H. IEC Design N motors have similar performance characteristics to NEMA Design B motors, while IEC Design H motors are similar to NEMA Design C motors. Because many motors imported into the U.S. are built to IEC specifications instead of NEMA specifications, DOE is proposing to include a definition for IEC Design N and IEC Design H motor types to ensure that these functionally similar motors are treated in a manner consistent with equivalent NEMA-based electric motors and to retain overall consistency with the existing definitional framework.

DOE's proposed definition for “IEC Design N motor” incorporates language from IEC Standard 60034-12 (2007 Ed. 2.1) (IEC 60034) with some modifications that would make the definition more comprehensive. IEC 60034 defines IEC Design N motors as being “normal starting torque three-phase cage induction motors intended for direct-across the line starting, having 2, 4, 6 or 8 poles and rated from 0,4 kW to 1 600 kW,” with torque characteristics and locked-rotor characteristics detailed in subsequent tables of the standard.
11

A similar approach for IEC Design H motors is taken in IEC 60034, but with references to different sections and slightly different wording. DOE is proposing to include all references to tables for torque characteristics and locked-rotor characteristics as part of these definitions to improve their comprehensiveness. As detailed in the proposed regulations below, today's proposed rule defines an “IEC Design N motor” as an induction motor designed for use with three-phase power with the following characteristics: a cage rotor, intended for direct-on-line starting, having 2, 4, 6, or 8 poles, rated from 0.4 kW to 1600 kW, and conforming to IEC specifications for torque characteristics, locked rotor apparent power, and starting. An “IEC Design H motor” is defined as an induction motor designed for use with three-phase power with the following characteristics: a cage rotor, intended for direct-on-line starting, with 4, 6, or 8 poles, rated from 0.4 kW to 160 kW, and conforming to IEC specifications for starting torque, locked rotor apparent power, and starting.

11
Across-the-line (or direct-on-line) starting is the ability of a motor to start directly when connected to a polyphase sinusoidal power source without the need for an inverter.

Electric motors that meet these performance requirements and

otherwise meet the definitions of general purpose electric motor (subtype I) or (subtype II) are already required to satisfy DOE's energy conservation standards at specified horsepower ranges. Because these IEC definitions stipulate a set of performance parameters that do not inhibit an electric motor's ability to be tested, DOE is not proposing any additional test procedure amendments at this time. However, DOE requests comment on the proposed definitions.

3. Electric Motors With Sealed and Moisture Resistant Windings

All electric motors have “insulation systems” that surround the various copper winding components in the stator. The insulation, such as a resin coating or plastic sheets, serves two purposes. First, it helps separate the three electrical phases of the windings from each other and, second, it separates the copper windings from the stator lamination steel. Electric motors with encapsulated windings have additional insulation that completely encases the stator windings, which protects them from condensation, moisture, dirt, and debris. This insulation typically consists of a special material coating, such as epoxy or resin that completely seals the stator's windings. Encapsulation is generally found on open-frame motors, where the possibility of contaminants getting inside the motor is higher than for an enclosed-frame motor.

In the electric motors preliminary analysis TSD,
12

DOE set forth a possible definition for the term “encapsulated electric motor.” The definition presented was based upon a NEMA definition for the term “Machine with Sealed Windings” and was intended to cover motors containing special windings that could withstand exposure to contaminants and moisture. As highlighted in NEMA and Baldor's comments, NEMA MG1-2009 does not specify a single term that encompasses a motor with encapsulated windings. Instead, NEMA MG1-2009 provides two terms: one for a “Machine with Sealed Windings” and one for a “Machine with Moisture Resistant Windings.” A definition for the term “Machine with Encapsulated Windings” has not appeared in MG1 since the 1967 edition. Because of potential confusion, NEMA asked DOE to clarify which type of motor, or possibly both, DOE was considering covering. (Baldor, Pub. Mtg. Tr., EERE-2010-BT-STD-0027-0060 at p 52; NEMA, EERE-2010-BT-STD-0027-0054 at p. 33)

12
The preliminary TSD published in July 2012 is available at:
http://www.regulations.gov/#!documentDetail;D=EERE-2010-BT-STD-0027-0023.

After reviewing the two pertinent definitions, the comments from Baldor and NEMA, and DOE's own research on these types of motors, DOE believes that motors that meet both definitions should be covered by any proposed definition and be included within its expanded scope of coverage. The ability for a motor's windings to continue to function properly when the motor is in the presence of moisture, water, or contaminants, as is the case when a motor meets one of these two definitions, does not affect its ability to be connected to a dynamometer and be tested for efficiency. Additionally, this ability does not preclude a motor from meeting the nine criteria that DOE is preliminarily using to characterize the electric motors that are within the scope of DOE's regulatory authority. Therefore, DOE is proposing two definitions based on the NEMA MG1—2009 definitions of a “Machine with Moisture Resistant Windings” and a “Machine with Sealed Windings.” DOE's proposed definitions are based on modified versions of the NEMA MG1—2009 definitions in order to eliminate potential confusion and ambiguities. The proposed definitions emphasize the ability of motors to pass the conformance tests for moisture and water resistance, thereby identifying them as having special or definite purpose characteristics. As detailed in the proposed regulations below, today's proposed rule defines “electric motor with moisture resistant” as an electric motor engineered to pass the conformance test for moisture resistance as specified in NEMA MG1-2009. An “electric motor with sealed windings” is defined as an electric motor engineered to pass the conformance test for water resistance as specified in NEMA MG1-2009.

In addition to proposing a definition for these motor types, DOE also considered difficulties that may arise during testing when following IEEE Standard 112 Test Method B or CSA C390-10 or any potential impacts on efficiency caused by encapsulation of the windings. While DOE received comment advocating the regulation of motors with special windings, it did not receive any comments suggesting or raising any necessary test procedure changes that would need to be made as a result of the stator winding encapsulation. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 14) Subsequently, DOE conducted its own research and consulted with testing laboratories and various industry experts regarding any effects that specially insulated windings may have on testing or efficiency.

As a result of these discussions, DOE does not believe that the presence of specially insulated stator windings in an electric motor would interfere with DOE-prescribed test procedures. Also, because temperature measurements are taken by measuring the stator winding resistance, DOE does not believe that the insulation on the stator windings themselves would interfere with carrying out any part of IEEE Standard 112 (Test Method B) or CSA C390-10, both of which require temperature measurements to be taken during testing. The modifications made to stator windings have no impact on a motor's ability to be connected to a dynamometer because they are modifications to the internal portions of the motor. Therefore, at this time, DOE is not proposing any test procedure amendments for electric motors with moisture resistant windings or electric motors with sealed windings.

DOE believes that the effects that specially insulated windings may have on an electric motor's efficiency are likely to be minimal. Although DOE recognizes there could be a change in the thermal characteristics of the motor, DOE believes that the additional treatment given to these specially insulated windings could, in some cases, improve heat dissipation. Again, however, DOE does not believe that the efficiency changes, whether positive or negative, will be significant. DOE requests any data, information, or comments regarding the effects of specially insulated stator windings on electric motor efficiency.

DOE also seeks comment on its proposed definition for motors with moisture resistant windings and motors with sealed windings and its preliminary decision not to propose additional testing instructions for these motors types.

4. Inverter-Capable Electric Motors

DOE currently regulates single speed motors with a 2-, 4-, 6-, or 8-pole configuration. Each of these motors operates at a constant rotational speed, which is predicated by its pole configuration. This means that the motor shaft is engineered to rotate at the same speed, regardless of its application or required power. In addition to its

pole configuration, a motor's rotational speed is partially determined by the frequency of its power source. The equation determining a motor's theoretical maximum speed (or synchronous speed) is:

EP26JN13.001

Inverter drives (also called variable-frequency drives (VFDs), variable-speed drives, adjustable frequency drives, alternating-current drives, microdrives, or vector drives) operate by changing the frequency and voltage of the power source that feeds into an electric motor. The inverter is connected between the power source and the motor and provides a variable frequency power source to the motor. The benefit of the inverter is that it can control the frequency of the power source fed to the motor, which in turn controls the rotational speed of the motor. This allows the motor to operate at a reduced speed when the full, nameplate-rated speed is not needed. This practice can save energy, particularly for fan and pump applications that frequently operate at reduced loading points. Inverters can also control the start-up characteristics of the motor, such as locked-rotor current or locked-rotor torque, which allows a motor to employ higher-efficiency designs while still attaining locked-rotor current or locked-rotor torque limits standardized in NEMA MG1-2009.
13

13
Li, Harry.
Impact of VFD, Starting Method and Driven Load on Motor Efficiency.
2011. Siemens Industry, Inc.

Currently, being suitable for use on an inverter alone would not exempt a motor from having to satisfy any applicable energy conservation requirements because it does not preclude a motor from meeting the nine design characteristics of electric motors that will define regulatory coverage. In today's NOPR, DOE is maintaining this approach. However, today's NOPR seeks to further clarify this position by proposing a definition for the term “inverter-capable electric motor.”

In its comments about the electric motors preliminary analysis, NEMA provided suggestions on how to define inverter capable-electric motors. NEMA agreed with DOE that these motors are capable of both operating with or without an inverter. However, NEMA stressed that these electric motors are primarily engineered to be used without an inverter and, in its view, this fact should be evident by the definition DOE ultimately adopts. NEMA also provided a suggested definition for the term “inverter-capable electric motor.” (NEMA, EERE-2010-BT-STD-0027-0054 at pp. 34-35) This definition, similar in substance and meaning to the definition that DOE presented in the electric motors preliminary analysis but including a few minor word changes, is consistent with DOE's understanding. As detailed in the proposed regulations below, today's proposed rule defines an “inverter-capable electric motor” as an electric motor designed to be directly connected to polyphase, sinusoidal line power, but that is also capable of continuous operation on an inverter drive over a limited speed range and associated load.

Because this motor type operates like a typical, general purpose electric motor when not connected to an inverter, DOE does not believe any test procedure amendments are needed. Under DOE's proposed approach, an inverter-capable electric motor would be tested without the use of an inverter and rely on the procedures used when testing a general purpose electric motor. DOE requests comments on its proposed definition and its tentative decision not to specify any test procedure instructions for this motor type beyond that which is already contained in the current procedure.

5. Totally Enclosed Non-Ventilated Electric Motors

Most enclosed electric motors are constructed with a fan attached to the shaft, typically on the end opposite the driven load, as a means of pushing air over the surface of the motor enclosure, which helps dissipate heat and reduce the motor's operating temperature. Totally enclosed non-ventilated (TENV) motors, however, have no fan blowing air over the surface of the motor. These motors rely, instead, on the conduction and convection of the motor heat into the surrounding environment for heat removal, which results in a motor that operates at higher temperatures than motors with attached cooling fans. TENV motors may be used in environments where an external fan could clog with dirt or dust, or applications where the shaft operates at too low of a speed to provide sufficient cooling (i.e., a motor controlled by an inverter to operate at very low revolutions per minute). TENV motors may employ additional frame material as well as improved stator winding insulation so that the motor may withstand the increased operating temperatures. Extra frame material allows for more surface area and mass to dissipate heat, whereas higher-grade stator winding insulation may be rated to withstand the higher operating temperatures.

In view of the statutory definitional changes created by EISA 2007, and the support expressed by both industry and energy efficiency advocates, DOE is analyzing TENV motors in the energy conservation standards rulemaking. (Motor Coalition, EERE-2010-BT-STD-0027-0035 at p. 19) As part of this effort, DOE proposes to add a definition for this motor type based on the definition of a “totally enclosed nonventilated machine” in paragraph 1.26.1 of NEMA MG1-2009. DOE tentatively concludes that this definition is accurate and sufficiently clear and concise and is proposing that the definition be adopted with minor alterations. As detailed in the proposed regulations below, today's proposed rule defines a “TENV electric motor” as an electric motor built in a frame-surface cooled, totally enclosed configuration that is designed and equipped to be cooled only by free convection.

In addition to proposing a definition for these motors, DOE considered whether any modifications to the test procedure may be necessary to test TENV motors. Prior to the electric motors preliminary analysis, ASAP and NEMA submitted comments suggesting that manufacturers could demonstrate compliance with the applicable energy conservation standards by testing similar models. (ASAP and NEMA, EERE-2010-BT-STD-0027-0012 at p. 7) Although NEMA and ASAP suggested this was a possible way to test these motors to demonstrate compliance, they did not state that this was necessary because of testing difficulties. Subsequently, after DOE published its electric motors preliminary analysis, NEMA stated that it was not aware of any changes that were required to use IEEE Standard 112 (Test Method B) when testing TENV motors. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 16) The Copper Development Association (CDA) commented that DOE may need to develop new test procedures for these motor types but did not explain why such a change would

be necessary. (CDA, EERE-2010-BT-STD-0027-0018 at p. 2) CDA did not indicate whether the current procedures could be modified to test these motors or what specific steps would need to be included to test these types of motors. Additionally, DOE knows of no technical reason why a TENV motor could not be tested using either IEEE Standard 112 (Test Method B) or the CSA-C390 procedure without modification. In view of NEMA's most recent comments suggesting that IEEE Standard 112 (Test Method B) is an appropriate means to determine the efficiency of these motors, and the fact that the CDA did not provide an explanation of why changes would be necessary, DOE is not proposing any test procedure amendments for TENV electric motors.

DOE requests comments on its proposed definition and preliminary decision not to propose any test procedure amendments for TENV electric motors.

D. Electric Motor Types Requiring Definitions and Test Procedure Instructions

DOE is proposing to add definitions for a number of electric motor types that are already commonly understood, but not necessarily clearly defined, by the industry. DOE is also proposing clarifying language for testing each of these motor types.

1. Immersible Electric Motors and Electric Motors With Contact Seals

Most electric motors are not engineered to withstand immersion in liquid (e.g., water, including wastewater). If liquid enters an electric motor's stator frame, it could create electrical faults between the different electrical phases or electrical steel and could impede rotor operation or corrode internal components. Immersible motors are electric motors that are capable of withstanding immersion in a liquid without causing damage to the motor. Immersible motors can withstand temporary operation in liquid, sometimes up to two weeks, but also run continuously outside of a liquid environment because they do not rely on the liquid to cool the motor. According to test 7 in Table 5-4 of NEMA MG1-2009, for a motor to be marked as protected against the effects of immersion, a motor must prevent the ingress of water into the motor while being completely submerged in water for a continuous period of at least 30 minutes. Therefore, DOE interprets “temporary” to mean a period of time of no less than 30 minutes. Immersible motors can operate while temporarily submerged because they have contact seals that keep liquid and other contaminants out of the motor. Additionally, some immersible motors may have pressurized oil inside the motor enclosure, which is used in conjunction with contact seals to prevent the ingress of liquid during immersion. Finally, immersible motors are occasionally constructed in a package that includes another, smaller (e.g.,
1/2
horsepower) motor that is used to improve cooling when the immersible motor is not submerged in water. In these cases, the two motors are constructed in a totally enclosed blower-cooled (TEBC) frame and sold together.

In responding to the October 15, 2010 framework document, NEMA and ASAP commented that greater clarification is needed with regard to immersible motors and how to differentiate them from liquid-cooled or submersible motors. (NEMA and ASAP, EERE-2010-BT-STD-0027-0012 at p. 9) DOE understands the general differences to be as follows:

1. Submersible motors are engineered to operate only while completely surrounded by liquid because they require liquid for cooling purposes,

2. Liquid-cooled motors use liquid (or liquid-filled components) to facilitate heat dissipation but are not submerged in liquid during operation, and

3. Immersible motors are capable of operating temporarily while surrounded by liquid, but are engineered to work primarily out of liquid.

As a result, as detailed in the proposed regulations below, today's proposed rule defines an immersible electric motor as an electric motor primarily designed to operate continuously in free-air, but that is also capable of withstanding complete immersion in liquid for a continuous period of no less than 30 minutes.

The contact seals used by immersible motors to prevent the ingress of water or other contaminants have an effect on tested efficiency that generally changes over time. New seals are stiff, and provide higher levels of friction than seals that have been used and undergone an initial break-in period.
14

DOE understands that as the seals wear-in they will loosen and become more flexible, which will somewhat reduce friction losses. In its comments on the electric motors preliminary analysis, NEMA stated that immersible motors should be tested with their contact seals removed. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 18)

14

Guide for the Use of Electric Motor Testing Methods Based on IEC 60034-2-1.
May 2011. Version 1.1. 4E, Electric Motors Systems, EMSA, available at:
http://www.motorsystems.org/files/otherfiles/0000/0113/guide_to_iec60034-2-1_may2011.pdf
and Neal, Michael J.
The Tribology Handbook Second Edition.
Page C26.5.

DOE discussed testing immersible electric motors with industry experts, SMEs, and testing laboratories, all of whom suggested that the seals should be removed prior to testing to eliminate any impacts on the tested efficiency. Given the break-in period considerations discussed above, DOE sought to confirm the effects of contact seals by conducting its own testing. DOE procured a five-horsepower, two-pole, TENV motor for this purpose.
15

Upon receipt of the motor, DOE's testing laboratory followed IEEE Standard 112 (Test Method B) and tested the motor as it was received, with the contact seals in place (test 1). After completing that initial test, the laboratory removed the contact seals and tested the motor again (test 2). Finally, the testing laboratory reinstalled the seals, ran the motor for an additional period of time such that the motor had run for a total of 10 hours with the contact seals installed (including time from the initial test) and then performed IEEE Standard 112 (Test Method B) again (test 3).

15
The immersible motor tested by DOE was also a vertical, solid-shaft motor. The testing laboratory was able to orient the motor horizontally without any issues, thus being able to test the motor properly per IEEE 112 Test Method B.

DOE's testing confirmed the significant impact that contact seals can have on demonstrated efficiency. In the case of the five-horsepower, two-pole, TENV motor, the motor performed significantly better with the contact seals removed, demonstrating a reduction in motor losses of nearly 20 percent. DOE's testing also demonstrated a decaying effect of the contact seals on motor losses as they break-in over time. In this instance, the effect of the contact seals on motor losses was reduced, but not eliminated, after 10 hours of running the motor. The results of DOE's immersible motor testing are shown below.

Table III-2—Results of Immersible Motor Testing

Motor type

Nameplate
efficiency

Test 1
(percent)

Test 2
(percent)

Test 3
(percent)

Immersible Motor (also TENV and a vertical solid-shaft motor)
89.5
88.9
91.0
89.2

Although DOE's testing confirmed that the impacts from contact seals can be significant and may reduce over time, DOE is proposing test procedure instructions that differ from the recommendations offered by interested parties. DOE believes testing with the contact seals may better represent an immersible motor's installed efficiency. DOE does not have specific data showing how the impacts from contact seals decay over time and DOE believes this decay may vary by basic model of immersible motor. In absence of such data showing near equivalent performance of immersible motors that are tested without contact seals to those that have contact seals that have been broken in, DOE is proposing that these motors be tested with the contact seals in place. In addition, DOE is proposing an allowance of a maximum run-in period of 10 hours prior to performing IEEE Standard 112 (Test Method B). This run-in period is intended to allow the contact seals a sufficient amount of time to break-in such that test conditions are equal or very similar to normal operating conditions that will be experienced by a user. DOE's proposed 10-hour maximum is a preliminary estimate obtained through discussions with electric motors testing experts. DOE may consider a longer run-in period or potentially removing the seals prior to testing in the final rule if data are obtained from manufacturers that substantiate the claim that an immersible motor's contact seals will wear-in, early on during the motor's lifetime (i.e., 200 hours), and to the point that the motor's efficiency is not affected. DOE is soliciting comments on its 200 hour assumption in its early motor lifetime estimate.

Finally, with regard to immersible motors built in a TEBC configuration, DOE is proposing instructions that would require the testing laboratory to power the smaller blower motor from an alternate power source than the one used for the electric motor being tested for efficiency. This approach will allow the testing laboratory to isolate the performance of the motor under test while continuing to provide the necessary cooling from the blower motor.

DOE requests comments concerning its proposed definition for “immersible electric motor,” especially with respect to differentiating this motor type from “liquid-cooled” and “submersible” motors. Additionally, DOE invites comment on its proposal to permit manufacturers to run their motors for a period of time prior to performing IEEE Standard 112 (Test Method B) to break-in any contact seals. In particular, DOE requests comment and any data on the appropriateness of the proposed 10-hour time limit allowable for the run-in period. Finally, DOE requests comment on the appropriateness of allowing manufacturers to use an alternative power source to run the blower motor while testing an immersible motor built in a TEBC frame.

2. Integral and Non-Integral Brake Electric Motors

In most applications, electric motors are not required to stop immediately; instead, electric motors typically slow down and gradually stop after power is removed from the motor, due to a buildup of friction and windage from the internal components of the motor. However, some applications require electric motors to stop quickly. Such motors may employ a brake component that, when engaged, abruptly slows or stops shaft rotation. The brake component attaches to one end of the motor and surrounds a section of the motor's shaft. During normal operation of the motor, the brake is disengaged from the motor's shaft—it neither touches nor interferes with the motor's operation. However, under these conditions, the brake is drawing power from the electric motor's power source and may be contributing to windage losses, because the brake is an additional rotating component on the motor's shaft. When power is removed from the electric motor (and brake component), the brake component de-energizes and engages the motor shaft, quickly slowing or stopping rotation of the rotor and shaft components.

There are two general types of brake motors—integral and non-integral brake motors. An electric motor falls into one of these two categories depending on how its brake component is connected to the motor. If the brake component is integrated with other components of the electric motor and not readily detachable, it is usually considered
16

an integral brake motor. Conversely, if the brake component is connected externally and is more readily detachable, it is considered a non-integral brake motor.

16
DOE's proposed definitions for integral and non-integral brake motors do not require a certain manner of attachment of the brake rather, the placement of the brake is the relevant distinctive factor.

In its August 15, 2012 “Joint Petition to Adopt Joint Stakeholder Proposal As it Relates to the Rulemaking on Energy Conservation Standards for Electric Motors” (the Petition), the Motor Coalition proposed a definition for the term “integral brake electric motor.” That definition stated that an integral brake electric motor is “an electric motor containing a brake mechanism either inside of the motor endshield or between the motor fan and endshield such that removal of the brake component would require extensive disassembly of the motor or motor parts.” (Motor Coalition, EERE-2010-BT-STD-0027-0035 at p. 19) Subsequent to the submission of the petition, DOE spoke with some of the Motor Coalition's manufacturers and its own SMEs. Based on these conversations, DOE believes that the Motor Coalition's definition is consistent with DOE's understanding of the term. In the electric motors preliminary analysis, DOE presented a definition of the term “integral brake motor” consistent with the definition proposed by the Motor Coalition. (For additional details, see Chapter 3 of the electric motors preliminary analysis Technical Support Document). However, upon further consideration, DOE believes that there may be uncertainty regarding certain aspects of the definition, particularly, what constitutes “extensive disassembly of the motor or motor parts.” Therefore, DOE is proposing a new definition that would remove this ambiguity. As detailed in the proposed regulations below, today's proposed rule defines an “integral brake electric motor” as an electric motor containing a brake mechanism either inside of the motor endshield or between the motor fan and endshield.

Conversely, the brake component of a non-integral brake motor is usually external to the motor and can be easily

detached without disassembly or adversely affecting the motor's performance. However, as with the definition of an “integral brake motor,” DOE reconsidered the definition it presented in its electric motors preliminary analysis TSD for “non-integral brake electric motor.” Similarly, DOE concluded that the previous definition was ambiguous, particularly with regards to detaching the brake component. Therefore, in today's notice, DOE is proposing a new definition for “non-integral brake electric motor” that parallels its proposed definition for “integral brake electric motor.” DOE believes that the new definition is clearer because it relies solely on the placement of the brake and not what level of effort is needed to remove it. Additionally, DOE believes that the structure of its two definitions encompasses all brake motors by requiring them to meet one definition or the other. As detailed in the proposed regulations below, DOE's proposed definition for a “non-integral brake electric motor” is an electric motor containing a brake mechanism outside of the endshield, but not between the motor fan and endshield.

DOE believes that a definition for both integral and non-integral brake electric motors is necessary to distinguish between the two motor types because DOE may consider requiring different setup procedures for the two motor types and holding them to different efficiency levels.

In the electric motors preliminary analysis, DOE stated that it had preliminarily planned to include integral brake motors in the scope of expanded energy conservation. The Motor Coalition suggested that DOE continue to exclude these motors from coverage because of potential complications with testing. The group explained that there are no test standards for this motor type and that removing the brake components from the motor would affect the motor's performance and possibly leave the motor inoperable because of the integrated nature of the removed brake components. The Motor Coalition added that the efficiency losses from brake componentry would not be uniform across the industry. (Motor Coalition, EERE-2010-BT-STD-0027-0035 at p. 13)

When considering test procedures for both brake motor types, DOE considered all the recommendations from the Motor Coalition and the results of its own testing. DOE conducted its own testing to gather information on the feasibility of testing integral and non-integral brake motors. During its investigation of integral brake motors, DOE procured and tested two motors: one five-horsepower, four-pole, TEFC motor and one one-horsepower, four-pole, TEFC motor. For each of the motors, DOE performed three tests. Each motor was initially tested following IEEE Standard 112 (Test Method B) as the motor was received (i.e., no modifications to the brake components). Then, the test laboratory removed the brake components and retested the motor, again following IEEE Standard 112 (Test Method B). Finally, a third test was conducted after the test laboratory reattached the brake components. The results of this testing are shown in Table III-3.

Table III-3—Results of Integral Brake Motor Testing

Motor type

Nameplate
efficiency
(percent)

Test 1
(percent)

Test 2
(percent)

Test 3
(percent)

Integral Brake Motor 1
87.5
86.4
87.2
86.0

Integral Brake Motor 2
82.5
77.4
80.3
78.0

For the two integral brake motors, there was no consistent amount of losses observed and attributable to the brake component. However, the decrease in motor losses that resulted when the brake was removed reached as high as 16 percent. While DOE anticipated that brake losses would vary based on motor horsepower and brake type, it appears that such losses are difficult to quantify in certain integral brake motor configurations. Additionally, while DOE found that the testing laboratory was able to reconnect the braking mechanisms after removal and to make the motor operable again after reconnecting the braking mechanism, there was a slight change in the performance of the two motors tested.

DOE also sought to investigate the feasibility of testing non-integral brake motors. DOE procured two non-integral brake motors, one five-horsepower, four-pole, TEFC motor and one 15-horsepower, four-pole, TEFC motor. When testing the motors, DOE's testing laboratory performed two tests on each motor. Initially, the motors were to be tested as they were received, following IEEE Standard 112 (Test Method B); however DOE's test facility faced a few complications. When attempting to test the five-horsepower motor, the test laboratory experienced complications when trying to conduct the no-load test. Because of the low voltage levels required for the no-load test, the braking mechanism would engage, stopping the test. Therefore, the testing laboratory spliced the electrical connections of the braking mechanism and connected the brake to an external power source. For the 15-horsepower motor, the brake had its own power connection and the test laboratory elected to connect the brake to an external power source (i.e., separate from what was supplied to the motor itself). For both motors, the test laboratory performed a second test in which the brake component was completely removed and the motor was tested according to IEEE Standard 112 (Test Method B) again. Finally, for the five-horsepower motor, the test laboratory performed a third test with the brake mechanism reattached.
17

The results of DOE's

non-integral

brake motor testing are shown below.

17
This motor was originally thought to be an integral brake motor, which is why it was tested a third time.

18
For this test, the brake would engage during the no-load test, thus the testing laboratory connected the brake to a separate power source for that test.

19
For this test, the laboratory connected the brake to an external power source for the duration of the test.

Table III-4—Results of Non-Integral Brake Motor Testing

Motor type

Nameplate
efficiency
(percent)

Test 1
(percent)

Test 2
(percent)

Test 3
(percent)

Non-Integral Brake Motor 1
87.5

18
87.3

87.7
87.1

Non-Integral Brake Motor 2
89.5

19
90.0

90.0

DOE obtained much useful information from both rounds of non-integral brake motor testing. For the five-horsepower motor (“non-integral brake motor 1”), DOE obtained additional test data that supports the notion that removing and reattaching a brake mechanism to a motor could affect its performance. In this case, when the brake was reattached, the demonstrated efficiency of the motor decreased, albeit a minimal amount that could simply be due to testing variation. For the 15-horsepower motor (“non-integral brake motor 2”) DOE obtained the same tested efficiency when the brake was powered externally and when it was removed. In this instance, this shows that there was a negligible impact on friction and windage losses due to the brake mechanism. DOE understands that this could have occurred for several reasons. It could be because the significant impacts on losses from brakes come from the power consumed to keep the brake disengaged. It could also be that the design of this particular brake mechanism was an anomaly and most brake mechanisms would have a larger impact on friction and windage. Finally, it could be because the motor tested was a 15-horsepower motor and the friction and windage losses due to the brake may have been small relative to other losses in the motor.

In light of the test results of the 15 horsepower, non-integral brake motor, DOE sought to investigate testing brake motors with the brake powered separately. Therefore, DOE conducted a final set of tests for the other three motors. During this testing the brake component was attached, but powered by a source separate from the motor. This testing showed that powering the brake component separately resulted in demonstrated efficiencies equivalent to testing a motor with the brake component completely removed. Results are shown in the Table below.

Table III-5—Comparison of Removing Brake and Powering Brake Separately

Motor tested

Tested
efficiency
with brake
removed
(percent)

Tested
efficiency
with brake
powered
separately
(percent)

Integral Brake Motor 1
87.2
87.6

Integral Brake Motor 2
80.3
80.4

Non-Integral Brake Motor 1
87.7
87.7

As a result of its testing of integral and non-integral brake electric motors, DOE is proposing the same test instructions for both motors types in today's notice. DOE proposes to include instructions that would require manufacturers to keep the brake mechanism attached to the motor, but to power it externally while performing IEEE Standard 112 (Test Method B). DOE believes that this is the best approach because it allows the test laboratory to isolate the losses due to the motor, which includes the friction and windage produced by the rotating brake mechanism. DOE believes that powering the motor and the brake mechanism separately during testing would ensure that the power consumed to keep the brake mechanism disengaged is not counted against the motor's tested efficiency. The power consumed to keep the brake mechanism disengaged represents useful work performed by the motor and should not be construed as losses, but it should be measured and reported. DOE believes this information is pertinent for brake motor consumers who wish to understand the energy consumption of their motor. Furthermore, when conducting the testing, DOE's test laboratory was able to splice connections and externally power the brake on multiple integral and non-integral brake motors, so DOE preliminarily believes that this process would not be unduly burdensome.

DOE requests comments on its proposed definitions. Additionally, DOE requests comments on its proposed instructions for testing integral and non-integral brake electric motors.

3. Partial Electric Motors

Most general purpose electric motors have two endshields,
20

which support the bearings and shaft while also allowing the shaft to rotate during operation. DOE understands that “partial electric motors,” also called “partial
3/4
motors,” or “
3/4
motors,” are motors that are sold without one or both endshields and the accompanying bearings. When partial electric motors are installed in the field, they are attached to another piece of equipment, such as a pump or gearbox. The equipment to which the motor is mated usually provides support for the shaft, thus allowing the shaft to rotate and drive its intended equipment. The equipment may also provide support for a shaft. When a partial electric motor is mated to another piece of equipment it is often referred to as an “integral” motor.
21

For example, an “integral gearmotor” is the combination of a partial electric motor mated to a gearbox. The gearbox provides a bearing or support structure that allows the shaft to rotate.

20
Endshields are metal plates on each end of the motor that house the motor's bearings and close off the internal components of the motor from the surrounding environment.

21
DOE notes that integral brake motors are not considered integral or partial motors.

DOE is aware that there are many different industry terms used to describe a partial electric motor and now that it is considering covering special and definite purpose electric motors in light

of the EISA 2007 changes to EPCA, DOE is proposing to define the term “partial electric motor” to ensure clarity. Additionally, because DOE considers integral gearmotors to be a subset of partial electric motors, this definition would also apply to integral gearmotors. Also, DOE does not wish to create confusion regarding the difference between a “component set” of an electric motor (discussed below in section III.G.2) and a “partial electric motor.” Therefore, as detailed in the proposed regulations below, today's proposed rule defines “partial electric motor” as an assembly of motor components necessitating the addition of no more than two endshields, including bearings, to create an operable motor. The “operable motor” means an electric motor engineered for performing in accordance with the applicable nameplate ratings.

DOE is aware that partial electric motors require modifications before they can be attached to a dynamometer for testing purposes. DOE received comments concerning potential testing difficulties for partial motors. The CDA indicated that a new test procedure may be required for partial motors and that DOE should consider developing a new test procedure for these and other motors. (CDA, No. 18 at p. 2) DOE has also received feedback suggesting that manufacturers could show compliance by testing a similar model that could more easily be attached to a dynamometer. (ASAP and NEMA, EERE-2010-BT-STD-0027-0012 at p. 9) In comments on the electric motors preliminary analysis, NEMA recommended that DOE require endshields to be installed prior to testing a partial motor. NEMA stated this would be an appropriate approach as long as the operating and cooling characteristics of a particular motor with endshields installed for testing is similar to how the partial motor would operate when connected to the driven equipment.
22

(NEMA, EERE-2010-BT-STD-0027-0054 at p 16)

22
Driven equipment is machinery that is run or “driven” by an electric motor.

DOE discussed NEMA's proposal and additional testing options with SMEs, testing laboratories, and motor industry representatives. Some interested parties suggested that the motor manufacturer could supply generic or “dummy” endplates equipped with standard ball bearings, which would allow for testing when connected to the partial electric motor. Alternatively, testing laboratories have considered machining the “dummy” endplates themselves, and supplying the properly sized deep-groove, ball bearings for the testing. Various testing laboratories have indicated the ability to perform this operation, but some added that they would require design criteria for the endplates from the original manufacturer of the motor. These laboratories noted that machining their own endplates could create motor performance variation between laboratories because it may impact airflow characteristics (and therefore thermal characteristics) of the motor.

DOE procured an integral gearmotor to determine the feasibility of testing partial electric motors. For this investigation, DOE purchased and tested one five-horsepower, four-pole, TEFC electric motor. DOE tested the motor twice, first with an endplate obtained from the manufacturer and second, with an endplate machined in-house by the testing laboratory. The results of these tests are shown below.

Table III-6—Results of Partial Electric Motor Testing

Motor type

Nameplate
efficiency
(percent)

Test 1
(percent)

Test 2
(percent)

Partial Electric Motor
81.0
83.5
82.9

As stated by testing laboratories, DOE found a variation in efficiency because of the endplate used during testing. In this case, DOE understands that the variation seen in tested efficiency was likely the result of varying the material used for the endplate. The endplate provided by the manufacturer was made of cast iron, while the endplate provided by the testing laboratory was machined from steel. The testing laboratory was not equipped to cast an iron endshield and replace the manufacturer's endshield with one of the same material. Additionally, DOE knows of no testing laboratory (other than a motor manufacturer), with such capability. DOE understands that the variance in the magnetic properties of steel likely produced small eddy currents in the endshield which increased heat and, therefore, losses within the motor.
23

Consequently, DOE believes that it is necessary to try and maintain a consistency in frame material, in order to prevent such variances in future testing.

23
Eddy currents are circulating currents induced in conductors (e.g., steel) by changing magnetic fields. They typically manifest themselves as heat, which can increase losses within an electric motor.

At this time, because of the possible variance that DOE found through its testing, DOE is proposing that an endplate be provided by the manufacturer of the motor and test with that endplate in place. If bearings are also needed, the test laboratory should use what DOE views as a “standard bearing”—a 6000-series, open, single-row, deep groove, radial ball bearing. DOE selected this set of specifications because it is common bearing type capable of horizontal operation. DOE requests comments on its proposed testing instructions for partial electric motors. In particular, DOE requests any data regarding the variation in tested efficiency likely to result from varying an endplate and its material.

E. Electric Motor Types Requiring Only Test Procedure Instructions

DOE is proposing to add additional instructions to the DOE test procedure that would affect a number of motor types for which DOE is analyzing new energy conservation standards. DOE is not proposing any definitions for these terms because DOE believes the terms are self-explanatory or already readily understood in the industry.

1. Electric Motors With Non-Standard Endshields or Flanges

Most electric motors are attached to a mounting surface by “mounting feet” or other hardware attached to the motor's housing, oftentimes on the bottom of the motor. However, some motors are mounted by directly attaching the motor's endshield, also called a faceplate, to a piece of driven equipment. If a motor's endshield protrudes forward to create a smooth mounting surface it may also be referred to as a flange, such as a Type D-flange or Type P-flange motor, as described in NEMA MG1-2009. Attaching a motor to the shaft of the driven equipment in this manner generally involves bolting the

motor to the equipment through mounting holes in the flange or faceplate of the motor.

NEMA MG1-2009, paragraphs 1.63.1, 1.63.2, and 1.63.3 designate Type C face-mounting, Type D flange-mounting, and Type P flange-mounting motors, respectively. These definitions provide reference figures in NEMA MG1-2009, section I, part 4 titled “Dimensions, Tolerances, and Mounting” that contain specifications for the standard mounting configurations and dimensions for these three motor types. The dimensions designate standard locations and dimensions for mounting holes on the faceplates or flanges of the motors. DOE is aware that some electric motors may have special or customer-defined endshields, faceplates, or flanges with mounting-hole locations or other specifications that do not necessarily conform to NEMA MG1-2009, Figure 4-3, “Letter Symbols for Type C Face-Mounting Foot or Footless Machines,” Figure 4-4, “Letter Symbols for Type D Flange-Mounting Foot or Footless Machines,” or Figure 4-5, “Letter Symbols for Vertical Machines.”

As previously explained DOE is considering setting energy conservation standards for special and definite purpose electric motors such as those motors with non-standard endshields. This change to the scope of energy conservation standards for electric motors means that the dimensions of a motor's endshields or flanges—neither of which impacts the efficiency or the ability to measure the efficiency of the motor—would no longer dictate whether a given motor would be required to meet energy conservation standards. Hence, DOE believes that an actual definition for such motors is unnecessary.

In evaluating the possibility of requiring these motor types to meet potential energy conservation standards, DOE is assessing whether these motors can be tested using non-standard flanges or endshields. DOE has received comments concerning the testing of these motor types. In response to the March 2011 RFI (76 FR 17577), ASAP and NEMA commented that motors with customer-defined endshields and flanged special motors should have their efficiency verified by testing a model motor with an equivalent electrical design that could more easily be attached to a dynamometer. (ASAP and NEMA, EERE-2010-BT-STD-0027-0020 at p. 4) NEMA added that testing motors with non-standard endshields may require a substitution of the special endshields with more conventional endshields. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 15)

DOE understands that it may not be possible to attach motors with non-standard endshields to a testing laboratory's dynamometer. If such situation arises and a test laboratory is unable to reconfigure the motor without removal of the endplate such that attachment to a dynamometer is possible, DOE proposes that the custom endshield be replaced with one that has standard (i.e., in compliance with NEMA MG1) dimensions and mounting configurations. As with partial electric motors, such a replacement must be obtained through the manufacturer and be constructed of the same material as the original endplate.

DOE requests comment on its preliminary decision not to propose a definition for these motor types. DOE also requests comments on its proposed instructions for testing motors with non-standard endshields or flanges.

2. Close-Coupled Pump Electric Motors and Electric Motors With Single or Double Shaft Extensions of Non-Standard Dimensions or Additions

Close-coupled pump motors are electric motors used in pump applications where the impeller is mounted directly on the motor shaft. Such motors are typically built with different shafts (usually longer) than generic general-purpose electric motors. Section I, part 4 of NEMA MG1-2009 and IEC Standard 60072-1 (1991) specify standard tolerances for shaft extensions, diameters, and keyseats that relate to the fit between the shaft and the device mounted to the shaft. However, sometimes manufacturers provide shafts with a special diameter, length, or design because of a customer's special application. In 2011, DOE proposed to clarify its treatment of these types of motors and included a table with allowable shaft variations. 76 FR 648, 671-72 (January 5, 2011) This table was intended to enumerate the deviations from standard shaft dimensions that DOE would allow while still considering the motor to be a general purpose motor subject to energy conservation standards.

The guidance was intended to identify variations in shaft dimensions for a motor that would be covered as a general purpose electric motor under EPCA. However, in view of the EISA 2007 and AEMTCA 2012 amendments, DOE has preliminarily decided to expand the scope of regulatory coverage beyond the initial scope set by EPCA prior to these two amendments. As such, DOE believes that a motor's shaft alone, no matter what its dimensions or type, is an insufficient reason to exclude a motor from having to satisfy energy conservation standards. Further, DOE believes that it is not necessary to explicitly define a close-coupled pump electric motor or an electric motor with a single or double shaft extension of non-standard dimensions or additions because whether a shaft is built within the shaft tolerances defined by NEMA and IEC is unambiguous.

In considering applying standards to these types of motors, DOE is assessing whether motors with non-standard shaft dimensions or additions can be tested using accepted and established procedures. DOE received feedback concerning the testing of these motor types during and after the October 18, 2010, framework document public meeting. NEMA and ASAP submitted a joint comment noting that DOE could allow testing of a “similar model” motor with a standard shaft to enable the motor to be more easily tested on a dynamometer. (NEMA and ASAP, EERE-2010-BT-STD-0027-0012 at p. 8) In its comments about the electric motors preliminary analysis, NEMA added that special couplings or adapters may be needed to test motors with special shaft extensions, but noted that a motor's shaft extension has little to no effect on its efficiency. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 14)

DOE sought to investigate the feasibility of using coupling adapters for motors with extended shafts or shafts of unique design. To do this, DOE procured a close-coupled pump motor with an extended shaft. When this motor was received, DOE's testing laboratory had no problems attaching the motor to its dynamometer. The use of an adapter in this case, was not needed. However, DOE also conferred with experts at its testing laboratory and learned that coupling adapters were needed for motors with extended shafts or shafts of unique design, which it had tested in the past. As such, DOE is not aware of any motor shaft design that has prevented DOE's test laboratory from performing a proper test according to IEEE 112 Test Method B. Therefore, at this time, DOE agrees with the above NEMA comment and is proposing to include instructions for special couplings or adapters. In other words, if a testing facility cannot attach a motor to its dynamometer because of the motor's shaft extension, that facility should use a coupling or adapter to mount and test the motor. DOE understands that a motor's shaft configuration has minimal, if any, impact on overall motor efficiency, and believes that this approach is technologically feasible and will not result in any distortion of a motor's inherent efficiency when tested.

DOE seeks comment on its tentative approach declining to propose a definition for motors with non-standard shaft dimensions or additions. DOE also requests comment on its proposed instructions for testing such motors.

3. Vertical Electric Motors

Although most electric motors are engineered to run while oriented horizontally, some operate in applications that require a vertical orientation. A horizontally oriented motor has a shaft parallel to the floor (or perpendicular to the force of gravity), while a vertically oriented motor has a shaft perpendicular to the floor (or parallel to the force of gravity). Relative to horizontal motors, vertical motors have different designs made with different construction techniques so that the electric motor can be operated in a vertical position. These different designs can include modifications to the mounting configuration, bearing design, and bearing lubrication (a discussion regarding bearings can be found in the following section, III.E.4). Additionally, vertical motors can come with various shaft configurations, including with a solid or hollow shaft. An example of a typical application requiring a vertical motor is a pump used in a well or a pit.

At this time, DOE is not proposing a definition for any terms related to vertical electric motors. DOE believes definitions are not needed because there is no industry confusion or ambiguity in whether an electric motor is a vertical electric motor. Furthermore, whether an electric motor has a solid shaft or a hollow shaft is also unambiguous and without need for DOE clarification. Although defining a vertically mounted electric motor does not appear necessary, DOE believes instructions detailing how to configure and mount a vertical motor for testing in a horizontal position, including the motor's orientation and shaft characteristics, would be helpful in ensuring a proper and consistent testing set-up.

EISA 2007 classified vertical solid-shaft motors as subtype II motors and required them to be tested in a “horizontal configuration.” (42 U.S.C. 6311(13)(B)(v)) NEMA, ASAP, and the Motor Coalition submitted comments agreeing with the EISA 2007 provision and noted that vertical motors cannot be tested on a standard dynamometer because most dynamometers are designed to operate in conjunction with horizontally oriented electric motors. (NEMA, EERE-2010-BT-STD-0027-0013 at p. 5; NEMA and ASAP, EERE-2010-BT-STD-0027-0012 at p. 3; Motor Coalition, EERE-2010-BT-STD-0027-0035 at pp. 18 and 30) DOE confirmed this assertion with its test laboratory and subject matter experts. In view of the statutory requirement and current dynamometer testing configuration limits, DOE is proposing to test motors, which are otherwise engineered to operate vertically, in a horizontal position when determining efficiency.

Another consideration is the shaft of a vertical motor and whether it is solid or hollow. If a vertical motor has a solid shaft, then no further adjustments are needed after considering orientation, unless the motor contains a special shaft. (See section III.E.2) If a vertical motor has a hollow shaft, (i.e., an empty cylinder that runs through the rotor and typically attaches internally to the end opposite the drive of the motor with a special coupling) then additional instructions would be needed prior to testing for efficiency.

After publishing the preliminary analysis, DOE did not receive any public comments suggesting that the testing of a vertical, hollow-shaft motor in a horizontal position would be technologically infeasible or unduly burdensome, especially when compared to the testing of a vertical solid-shaft motor. DOE understands that vertical hollow-shaft motors may not have a shaft extension at the drive end of the motor, which would be necessary for attaching or coupling the motor to a dynamometer for testing.

DOE conducted testing to gauge the feasibility of testing a vertical, hollow-shaft motor. For its investigation, DOE purchased a five-horsepower, two-pole, TEFC vertical motor with a hollow shaft. Upon receipt of the motor, the testing laboratory found that the motor's bearing construction was sufficient for horizontal operation and no replacement would be needed. However, the motor did require a shaft extension to be machined. After a solid shaft was constructed, it was inserted into the hollow shaft and attached via welding to the lip of the hollow shaft. The testing laboratory encountered no further problems and was able to properly test the motor according to IEEE Standard 112 (Test Method B).

After conducting this testing, DOE believes that, as long as the attached solid-shaft maintains sufficient clearance through the drive end of the motor to enable the motor to be attached to the dynamometer this is a feasible approach to testing vertical hollow-shaft motors. Aside from the addition of a shaft extension, DOE does not believe that testing a vertical hollow-shaft motor in a horizontal configuration would add undue testing burden when compared to testing a solid-shaft vertical motor.

In response to the March 2011 RFI, NEMA suggested that vertical motors rated 1-500 horsepower be tested according to section 6.4 of IEEE Standard 112 (Test Method B—
Input-output with segregation of losses and indirect measurement of stray-load loss
), if bearing construction permits; otherwise, it suggested testing vertical motors according to section 6.6 of IEEE Standard 112 (Test Method E—
Electric power measurement under load with segregation of losses and direct measurement of stray-load loss
), as specified in NEMA MG1 paragraph 12.58.1 “Determination of Motor Efficiency and Losses.”
24

(NEMA, EERE-2010-BT-STD-0027-0019 at p. 4)

24
“Efficiency and losses shall be determined in accordance with IEEE Std 112 or Canadian Standards Association Standard C390. The efficiency shall be determined at rated output, voltage, and frequency. Unless otherwise specified, horizontal polyphase, squirrel-cage medium motors rated 1 to 500 horsepower shall be tested by dynamometer (Method B) [Footnote: CSA Std C390 Method 1] as described in Section 6.4 of IEEE Std 112. Motor efficiency shall be calculated using form B of IEEE Std 112 or the equivalent C390 calculation procedure. Vertical motors of this horsepower range shall also be tested by Method B if bearing construction permits; otherwise they shall be tested by segregated losses (Method E) [Footnote: CSA Std Method 2] as described in Section 6.6 of IEEE Std 112, including direct measurement of stray-loss load.” NEMA Standards Publication MG1-2009,
Motors and Generators,
paragraph 12.58.1

DOE consulted testing laboratories about whether IEEE Standard 112 (Test Method E) would be an appropriate procedure to use when testing vertical motors. DOE understands that the primary difference between IEEE Standard 112 Test Method B and Test Method E is that Test Method E uses a different method to calculate stray-load loss relative to Test Method B. Test Method B measures motor output power and uses this number as part of the calculation for stray-load loss. However, Test Method E does not require the measurement of output power, and, therefore, uses a different measurement method to directly find the stray-load loss. By not requiring the measurement of output power, Test Method E can be conducted on motors installed in an area or in equipment that cannot be attached to a dynamometer. Although Test Method E may reduce some testing burden for vertical motors, DOE is concerned that Test Method E could produce results that are inconsistent and inaccurate relative to testing comparable motors under Test Method B. Therefore, DOE is declining to propose the use of Test Method E for vertical motors. However, DOE requests additional comments and test data that demonstrate any differences in the

results of testing under Test Method E and Test Method B for the same basic model of vertical motor.

DOE requests comments on its preliminary decision not to propose any definitions for vertical motors. It also requests comments on its proposed instructions when addressing various construction differences between vertical and horizontal motors, in particular, test methods for vertical motors with hollow shafts.

4. Electric Motor Bearings

Electric motors usually employ antifriction bearings that are housed within the endshields to support the motor's shaft and provide a low-friction means for shaft rotation. Antifriction bearings contain rolling elements, which are the components inside the bearings that “roll” around the bearing housing and provide the reduced-friction means of rotation. Rolling elements can be spherical, cylindrical, conical, or other shapes. The design of the rolling element is selected based on the type and amount of force the shaft must be capable of withstanding. The two primary types of loads imposed on motor bearings are radial and thrust. Radial loads are so named because the load is applied along the radius of the shaft (i.e., perpendicular to the shaft's axis of rotation). Bearings may be subject to radial loads if the motor's shaft is horizontal to the floor (i.e., horizontally oriented). These bearings are called “radial bearings.” “Thrust bearings” are bearings capable of withstanding thrust loads, which are loads with forces parallel to the “axis” of the shaft (i.e., parallel to the shaft's axis of rotation) and may be encountered when the shaft is vertical to the floor (i.e., vertically oriented).

In addition to the type of force, bearings are also chosen based on the magnitude of the force they can withstand. While most applications use spherical rolling-elements, some motors employ cylindrical-shaped rolling-elements inside the bearings. These cylindrical-shaped rolling elements are called “rollers,” and this bearing type is referred to as a “roller bearing.” Roller bearings can withstand higher loads than spherical ball bearings because the cylindrically shaped rolling-element provides a larger contact area for transmitting forces. However, the larger contact area of the rolling element with the bearing housing also creates more friction and, therefore, may cause more losses during motor operation.

Regardless of the rolling element used, bearings must be lubricated with either grease or oil to further reduce friction and prevent wear on the bearings. Open or shielded bearing construction allows for the exchange of grease or oil during motor operation. Sealed bearings, unlike shielded or open bearings, do not allow the free exchange of grease or oil during operation. Sealed bearings incorporate close-fitting seals that prevent the exchange of oil or grease during the bearing's operational lifetime. Such bearings may be referred to as “lubed-for-life” bearings because the user purchases the bearings with the intention of replacing the bearing before it requires re-lubrication. Shielded bearings differ from open bearings in that shielded bearings contain a cover, called a “shield,” which allows the flow of oil or grease into the inner portions of the bearing casing, but restricts dirt or debris from contacting the rolling elements. Preventing dirt and debris from contacting the bearing prevents wear and increases the life of the bearing.

DOE also understands that certain vertical motors use oil-lubricated bearings rather than the grease-lubricated bearings that are typically found in horizontal motors. If a vertical motor contains an oil-lubricated system, problems can occur when the motor is reoriented into a horizontal position and attached to a dynamometer for testing. Because oil has a lower viscosity than grease, it could pool in the bottom of the now horizontally oriented (vertical motor) bearing.
25

Such pooling, or loss of proper lubrication to the bearings, could adversely affect the motor's performance, damage the motor, and distort the results of testing.

25
Viscosity is the measure of a liquid's resistivity to being deformed. An example of a material with high viscosity is molasses and an example of a material with low viscosity is water.

Because of the various construction and lubrication types, DOE understands that motors may contain bearings only capable of horizontal operation, vertical operation, or, in some limited cases, both horizontal and vertical operation. For those motors equipped with thrust bearings only capable of vertical orientation, DOE understands that reorienting the motor, as would be necessary for testing, could cause physical damage to the motor. For motors equipped with such bearings, DOE is proposing to add testing instructions that would require the testing laboratory to replace the thrust bearing with a “standard bearing,” which shall be interpreted as a 6000 series, open, single-row, deep groove, radial ball bearing, because that is the most common type of bearing employed on horizontally oriented motors. For any electric motor equipped with bearings that are capable of operating properly (i.e., without damaging the motor) when the motor is oriented horizontally, DOE is proposing that the motor should be tested as is, without replacing the bearings. DOE believes that this is the most appropriate approach because it will provide the truest representation of the energy use that will be experienced by the user.

In response to the preliminary analysis, DOE received comment specifically about testing electric motors with sleeve bearings. Sleeve bearings are another type of bearing that do not use typical rolling elements, but rather consist of a lubricated bushing, or “sleeve,” inside of which the motor shaft rotates. The shaft rotates on a film of oil or grease, which reduces friction during rotation. Sleeve bearings generally have a longer life than anti-friction ball bearings, but they are more expensive than anti-friction ball bearings for most horsepower ratings.
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Both ASAP and NEMA asserted that a motor with sleeve bearings should have its efficiency verified by testing a motor of equivalent electrical design and which employs standard bearings.
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(ASAP and NEMA, EERE-2010-BT-STD-0027-0020 at p. 4) However, NEMA later revised its position in separately submitted comments to the electric motors preliminary analysis public meeting. NEMA stated that further review of pertinent test data indicated that sleeve bearings do not significantly impact the efficiency of a motor, and that a motor having sleeve bearings is not sufficient reason to exclude it from meeting energy conservation standards. (NEMA, NEMA, EERE-2010-BT-STD-0027-0054 at p. 17) NEMA also commented that it is not aware of any reason that a motor cannot be tested with sleeve bearings, but that DOE should also provide the option to test sleeve bearing motors with the sleeve bearing swapped out for anti-friction ball bearings. (NEMA, EERE-2010-BT-STD-0027-0054 at p. 17)

26
William R. Finley and Mark. M Hodowanec.
Sleeve Vs. Anti-Friction Bearings: Selection of the Optimal Bearing for Induction Motors.
2001. IEEE. USA.

27
Neither NEMA nor ASAP elaborated on what “standard” bearings are. DOE is interpreting “standard” bearings to mean spherical, radial ball bearings, because this is the most common type of bearing used for general purpose, horizontally oriented motors.

DOE separately consulted with testing laboratories, SMEs, and manufacturers and reviewed a pertinent technical paper.
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As a result of this collective

research, DOE has tentatively determined that sleeve bearings do not significantly degrade efficiency when compared to spherical, radial ball bearings. More importantly, DOE does not believe that it is any more difficult to attach a motor with sleeve bearings to a dynamometer than a standard, general purpose electric motor equipped with radial ball bearings. Additionally, DOE believes that swapping sleeve bearings with spherical, radial ball bearings may be time consuming and otherwise present unforeseen or undue difficulties because of the overall design of the motor that operates with the sleeve bearings. Motors that employ sleeve bearings have significantly different bearing-support configurations than motors that employ spherical, radial ball bearings, and DOE is not certain that sleeve bearings could be readily swapped with standard ball bearings without significant, costly motor alterations. Therefore, because it may be impracticable to swap them out with other bearings, DOE is proposing that motors with sleeve bearings be tested as-is and with the sleeve bearings installed.

28
William R. Finley and Mark. M Hodowanec.
Sleeve Vs. Anti-Friction Bearings: Selection of the Optimal Bearing for Induction Motors.
2001. IEEE. USA.

DOE requests comment regarding its proposed approach to testing motors with thrust bearings only capable of vertical operation. DOE also requests comment on its proposed approach to testing motors with all types of bearings that are capable of horizontal operation, in particular, its proposed approach to testing motors with sleeve bearings.

F. General Clarification for Certain Electric Motor Types

For some electric motor types, DOE is neither proposing additions to the DOE test procedure nor proposing to define the motor types. However, DOE believes that some general clarification is needed for the following electric motor types to ensure that the regulations have sufficient clarity in detailing whether a particular motor is covered by DOE's regulations.

1. Electric Motors With Non-Standard Bases, Feet or Mounting Configurations

DOE has not yet regulated special or definite purpose motors, or general purpose motors with “special bases or mounting feet,” because of the limits prescribed by the previous statutory definition of “electric motor.” That definition included a variety of criteria such as “foot-mounting” and being built in accordance with NEMA “T-frame” dimensions, which all narrowed the scope of what comprised an electric motor under the statute. (See 42 U.S.C. 6311(13)(A) (1992)) As a result of EISA 2007 and related amendments that established energy conservation standards for two subtypes of general purpose electric motors (subtype I and subtype II), among other motor types, the statutory meaning of the term, “general purpose motor” was broadened to include, for example, “footless motors.” Similarly, because definite and special purpose motors now fall under the broad statutory heading of “electric motors,” DOE is considering whether to set standards for electric motors with non-standard bases, feet, or mounting configurations.

Part 4 of section I in NEMA MG1-2009 provides general standards for dimensions, tolerances, and mounting for all types of electric motors. In that section, figures 4-1 through 4-5 identify the letter symbols associated with specific dimensions of electric motors with various bases, feet, and mounting configurations. Accompanying these figures are tables throughout part 4 of section I that specify dimensions, explain how a particular dimension is measured and detail the applicable measurement tolerances. This collective information is used to standardize the dimensions associated with specific frame sizes, given a certain base, feet, or mounting configuration. The IEC provides similar information in its standard, IEC Standard 60072-1, “Dimensions and output series for rotating electrical machines.” Although the majority of motors are built within these specifications, DOE is aware that some motors may have feet, bases, or mounting configurations that do not necessarily conform to the industry standards. These are the motors—i.e. those not conforming to NEMA or IEC standards for bases, feet, or mounting configurations—that DOE is considering regulating.

DOE believes that a definition is not needed for this particular type of electric motor because whether a motor has a mounting base, feet, or configuration that is built within compliance of the standard dimensions laid out in NEM

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2013-15132. Public record. Not legal advice.