Section 220.50 Electrical Equipment-General

Section 220

Section 220.50  Electrical

Equipment-General

a)         Electric power circuits and electric equipment;

deenergization.

Power circuits and electric equipment shall be deenergized

before work is done on such circuits or equipment, except when necessary for

trouble-shooting or testing.  Disconnecting devices shall be locked out and

suitably tagged by the persons who perform such work, except that in cases

where locking out is not possible, such devices shall be opened and suitably

tagged by such persons.  Locks and tags shall be removed only by the persons

who installed them, or, if such persons are unavailable, by persons authorized

by the operator or his agent.

b)         Electric circuits and equipment; repair.

No electrical work shall be performed on electric circuits or

equipment except by a person qualified to perform electrical work and to

maintain electrical equipment, or by a person trained to perform electrical

work and to maintain electrical equipment at the direction of a qualified

person. When such work is done by a trained person, the circuits or equipment

shall be examined by a qualified person to assure safe operating condition

before such circuits or equipment are energized.

c)         Electric equipment; examination, testing, and maintenance.

Electric equipment shall be frequently examined, tested and

properly maintained by a person qualified to perform electrical work and to

maintain electrical equipment to assure safe operating conditions.  When a

potentially dangerous condition is found on electric equipment, such equipment

shall be identified and be removed from service until such condition is

corrected.  A record of such examinations shall be kept in an approved book, and

shall include all dangerous conditions found, corrective actions taken, and the

signature of the qualified person conducting the examination or testing

ns.  When a

potentially dangerous condition is found on electric equipment, such equipment

shall be identified and be removed from service until such condition is

corrected.  A record of such examinations shall be kept in an approved book, and

shall include all dangerous conditions found, corrective actions taken, and the

signature of the qualified person conducting the examination or testing.  The

record of examinations shall be signed by the person responsible for

maintaining the equipment in safe operating condition, who shall also be a

person qualified to perform electrical work and maintain electrical equipment,

and records shall be made available for inspection by an authorized

representative of the Department and the authorized representative of miners of

such mine.

d)         Electric equipment; examination and testing.

A potentially dangerous condition within the meaning of

Section 220.50(c) shall include without limitation, exposed conductors,

improper frame grounding, missing guards, missing inspection covers,

poorly-made splices in conductors, improper terminations, improper overload or

short circuit protection, broken conduit, missing or malfunctioning safety

devices, inoperative indicating lights, inoperative ground fault protection, defective

monitoring circuits, and inadequate ground fields.

e)         Qualified person.

A qualified person within the meaning of Sections 220.50(b),

220.50(c), 220.60(b), 220.80(b) and Section 220.90 of this Part is an

individual who has been qualified as a coal miner electrician under 30 CFR

77.103, or anyone who may be so qualified in the future as a coal miner

electrician by the Department, if and when such Department adopts rules

affecting coal miner electrician certification.

f)         Electric equipment; frequency of examination and testing

), 220.60(b), 220.80(b) and Section 220.90 of this Part is an

individual who has been qualified as a coal miner electrician under 30 CFR

77.103, or anyone who may be so qualified in the future as a coal miner

electrician by the Department, if and when such Department adopts rules

affecting coal miner electrician certification.

f)         Electric equipment; frequency of examination and testing.

The examinations and test required under the provisions of

Section 220.50(c) shall be conducted as interpreted in the Mining Enforcement

Safety Administration (MESA) Inspector's Manual at least monthly or more often

if necessary to assure safe operating conditions.  State Mine Inspectors shall

be presented evidence of qualifications upon request.

g)         Electric conductors; capacity and insulation.

Electric conductors shall be sufficient in size and have

adequate current-carrying capacity and be of such construction that a rise in

temperature resulting from normal operation will not damage the insulating

materials.

h)         Electric Conductors.

Electric conductors, installed inside surface buildings and

structures, shall be sufficient in size to meet the minimum current-carrying

capacity provided for in the National Electrical Code in effect at the time of

installation.

i)          Electric conductors; mobile and portable equipment.

Trailing cable, portable cables, and electric conductors

installed in mobile or portable equipment shall have ampacities and

construction in accordance with the specifications of Insulated Power Cable

Engineers Association-National Electrical Manufacturers Association in effect

at time of purchase and the conductors shall be sufficient in size so that a

rise in temperature resulting from normal operation will not damage the

insulating material.

j)          Electrical connections or splices; suitability

pacities and

construction in accordance with the specifications of Insulated Power Cable

Engineers Association-National Electrical Manufacturers Association in effect

at time of purchase and the conductors shall be sufficient in size so that a

rise in temperature resulting from normal operation will not damage the

insulating material.

j)          Electrical connections or splices; suitability.

Electrical connections or splices in electric conductors

shall be mechanically and electrically efficient, and suitable connectors or

approved splicing methods shall be used.  All electrical connections or splices

in insulated wire and cable shall be reinsulated at least to the same degree of

protection as the remainder of the wire or cable.

k)         Cable fittings; suitability.

Cables shall enter metal frames of motors, splice boxes, and

electric compartments only through proper fittings and shall be secured to prevent

chaffing of the insulation.  When insulated wires, other than wiring installed

in conduit, pass through metal frames, the holes shall be substantially bushed

with insulated bushings and the wires be secured.

l)          Electric equipment and circuits; overload, short-circuit, and

ground fault protection.

Automatic circuit-breaking devices or fuses of the correct

type and capacity shall be installed so as to protect all electric equipment

and circuits against short circuit and overloads.  Ground fault protection

shall be provided for equipment, powered by solidly or resistance grounds'

systems.

m)        Electric equipment and circuits; overload and short-circuit

protection; minimum requirements

tomatic circuit-breaking devices or fuses of the correct

type and capacity shall be installed so as to protect all electric equipment

and circuits against short circuit and overloads.  Ground fault protection

shall be provided for equipment, powered by solidly or resistance grounds'

systems.

m)        Electric equipment and circuits; overload and short-circuit

protection; minimum requirements.

Devices providing short-circuits and overload protection

shall conform to the minimum requirements for protection of electric circuits

and equipment of the National Electrical Code in effect at the time of

installation except that motors and circuits used in specially designed

electrical systems, such as those used on some excavators, hoists and

elevators, shall be considered as being provided with overload protection if

the design of the system prevents the motors and associated circuits from being

subjected to harmful overloads.

n)         Electric equipment-switches.

All electric equipment contracted for after the effective

date of this regulation shall be provided with switches or other controls that

are safely designed, constructed, and installed.  The voltage of alternating

current remote control circuits that are installed external to the controller

enclosure shall not exceed one hundred twenty (120) volt.

o)         Lightning arresters; ungrounded, exposed power conductors, and

telephone wires.

All ungrounded, exposed power conductors, control lines, and

communication wires shall be equipped with suitable lightning arresters which

are adequately installed and connected to a low resistance grounding medium in

accordance with Section 220.70(f).

p)         Lightning arresters; circuits entering or leaving buildings.

Lightning arresters protecting circuits entering or leaving

buildings shall be provided at a point near where each such circuit enters or

leaves the building.

q)         Transformers and high-voltage equipment; installation and

guarding; minimum vertical clearance

ance grounding medium in

accordance with Section 220.70(f).

p)         Lightning arresters; circuits entering or leaving buildings.

Lightning arresters protecting circuits entering or leaving

buildings shall be provided at a point near where each such circuit enters or

leaves the building.

q)         Transformers and high-voltage equipment; installation and

guarding; minimum vertical clearance.

1)         Transformers and other high-voltage equipment shall be of the

enclosed type, or installed in a transformer house, or surrounded by a

substantial fence at least six (6) feet high and at least three (3) feet from

any energized parts, casings, or wiring.

2)         Enclosures of high-voltage equipment shall be kept locked

against unauthorized entry.

3)         Electric equipment energized at more than one thousand (1,000)

volts and containing unguarded live parts, shall be installed with a minimum

vertical clearance above the surfaces where a person would normally stand, as

follows:

Voltage

Between Phases

Minimum

Vertical Clearance of Unguarded Parts:

Feet

Inches

1,000

– 6,600

8

0

6,601

– 11,000

9

0

11,001

– 22,000

9

3

22,001

– 33,000

9

6

33,001

– 44,000

9

10

44,001

– 66,000

10

5

66,001

– 88,000

11

0

88,001

– 110,000

11

7

110,001

– 132,000

12

2

r)          Resistors; location and guarding.

Resistors, heaters, and rheostats shall be located so as to

minimize fire hazards and, where necessary, provided with guards to prevent

personal contact.

s)         Danger signs at high-voltage electrical installations.

Danger signs shall be posted at the entrance to all

high-voltage electrical installations.

t)          Inspection and cover plates.

Inspection and cover plates on electrical equipment shall be

kept in place at all times except during testing or repairs.  Equipment

designed with exposed energized parts shall be properly guarded to prevent

accidental contact.

u)         Insulated platforms at power switches

shall be posted at the entrance to all

high-voltage electrical installations.

t)          Inspection and cover plates.

Inspection and cover plates on electrical equipment shall be

kept in place at all times except during testing or repairs.  Equipment

designed with exposed energized parts shall be properly guarded to prevent

accidental contact.

u)         Insulated platforms at power switches.

Insulated mats or platforms, insulated for the phase-to-phase

voltage of the system, shall be kept in place at all switchboards and power

control switches where shock hazards exist.  However, metal plates on which a

person normally would stand and which are kept at the same potential as the

grounded, metal noncurrent-carrying parts of the power switches to be operated,

may be used.

v)         Switchboards; enclosures, passageways, and clearance.

Switchboards in stationary installations which require back

access shall be provided with passageways or lanes of travel which permit

access to the back of the switchboard from both ends for inspection,

adjustment, or repair.  Openings permitting access to the rear of any

switchboard shall be guarded, except where they are located in buildings which

are kept locked. Enclosures containing switchboards motor generators sets,

transformers, oil circuit breakers, and resistance panels shall not be used for

the storage of material.

w)        Bare signal or control wires; voltage.

The voltage on bare signal or control wires accessible to

personal contact shall not exceed forty (40) volts.

x)         Electric Wiring and equipment; Installation and maintenance.

Except as otherwise provided in this Part, all wiring and

electrical equipment installed after effective date of this regulation shall

meet the requirements of the National Electric Code in effect at the time of

installation.

y)         Hazardous locations, surface facilities; bituminous and

lignite mines

forty (40) volts.

x)         Electric Wiring and equipment; Installation and maintenance.

Except as otherwise provided in this Part, all wiring and

electrical equipment installed after effective date of this regulation shall

meet the requirements of the National Electric Code in effect at the time of

installation.

y)         Hazardous locations, surface facilities; bituminous and

lignite mines.

1)         All electrical circuits and equipment installed after

effective date of this regulation with a coal preparation plant or other

enclosure housing coal-handling facilities, except in sections where only wet

coal is handled or in sections so maintained as to be free from dangerous amounts

of coal dust, shall be of the type designed for hazardous locations, Class II,

Group F, and installed in accordance with the requirements in Article 501 of

the National Electrical Code.

2)         Enclosed areas where methane may accumulate and is not prevented

from accumulating by an adequate ventilation system shall have electric

circuits and equipment of the type designed for hazardous locations, Class I,

Group D, and installed in accordance with the requirements in Article 501 of

the National Electrical Code.

3)         An adequate ventilation system within the meaning of paragraph

(b) above is a system in which:

A)        The enclosed area is monitored continuously in accordance with

the provisions of Section 220.20(n); and

B)        The provisions of Section 220.20(a) are complied with.

z)         Approved permissible equipment.

Permissible electrical equipment which is maintained in a

permissible condition may be used in lieu of equipment required in Section

220.50(y).

aa)       Minimum wiring requirements for stationary structures and

buildings; general

accordance with

the provisions of Section 220.20(n); and

B)        The provisions of Section 220.20(a) are complied with.

z)         Approved permissible equipment.

Permissible electrical equipment which is maintained in a

permissible condition may be used in lieu of equipment required in Section

220.50(y).

aa)       Minimum wiring requirements for stationary structures and

buildings; general.

1)         All wiring shall be installed so as to be adequately protected

from physical damage;

2)         Raceways, cable assemblies, boxes, cabinets, and fittings

shall be securely fastened in place;

3)         Cables, conductors, metal raceways, cable armor, boxes,

fittings, supports, and other wiring hardware shall be of proper construction

and material for the environment in which they are installed;

4)         Power cables within surface structures shall closely follow

the surface of the building or the other continuous support and shall be

secured at intervals not exceeding four and one-half (4 1/2) feet and within

one (1) foot from every box fitting; and

5)         All open conductors within surface structures shall closely

follow the surface of the building and be installed on proper insulators which

support the wires at least every four and one-half (4 1/2) feet.

bb)       Equipment marking.

All electrical equipment purchased or rebuilt after the

effective date of these rules shall be provided with a plate which indicates

the manufacturer's name, rated voltage, current, horsepower, frequency, number

of phases, and duty cycle.

cc)       Protection of power cables.

All power cables and wiring shall be adequately protected

against mechanical damage.  If a cable is damaged to the extent that the outer

jacket will not exclude moisture, or if the conductors or metallic shielding

are exposed, the cable jacket shall be repaired to the same degree of

protection as the remainder of the cable.

dd)      Identification

y cycle.

cc)       Protection of power cables.

All power cables and wiring shall be adequately protected

against mechanical damage.  If a cable is damaged to the extent that the outer

jacket will not exclude moisture, or if the conductors or metallic shielding

are exposed, the cable jacket shall be repaired to the same degree of

protection as the remainder of the cable.

dd)      Identification.

Circuit breakers, disconnects, control switches, and push

buttons shall be marked to show which circuit they control, unless

identification can be made readily by location.