Receptacles. Receptacles shall be provided at reasonable intervals
(not more than 25 ft (7.62 m)) in tunnels, along conveyers, on columns, around
peripheral walls, at equipment and in areas requiring maintenance, for
temporary lights and portable tools.
Motors and lights shall be power factor corrected.
10.14.2.1 Ratings. The selection of motor controllers, either manual or
magnetic, must include both current and voltage ratings. The controller must
be rated either in horsepower or both full-load and locked rotor current
values suitable for the application. Provide overload relays with heaters
selected according to the full-load current rating of the motor. Where fuses
are used for short-circuit protection, provide overload protection in each
phase of the motor circuit.
10.14.2.2 Magnetic Controllers. When selecting magnetic motor controllers,
consideration must also be given to the associated device for short-circuit
protection. Use a combination controller and fused switch, combination
controller and circuit breaker, or a controller and fuse and circuit breaker
combination. Select the combination that is suited for the type of use and
that will protect the branch circuit wiring and the starter from damage due to
10.14.2.3 Modifications. When selecting a controller, consider the
requirements of modifications of the basic device. Switchgear, transformers
and related equipment shall be installed with means of future expansion.
10.14.3.1 Criteria. Additional criteria for selection of motor controllers
and motor control centers are contained in NEMA No.IC-1, Standards of
Industrial Controls, and in MIL-HDBK-1004/3, Switchgear and Relaying.
10.14.3.2 Protection. The let-through energy from circuit breakers may
exceed the short time rating of some motor starters. Therefore, the interrupt
rating of the combination starter may not be the same as the breaker alone.
Choose fuses which permit the required motor accelerating times and the
necessary short circuit protection. Refer to MIL-HDBK-1004/3 for protective
devices and methods of limiting short circuit currents. Check manufacturer
data for combination starters and fuse ratings.
10.14.3.3 Enclosures. Select the enclosures suitable for the application
requirements in accordance with the ratings given in NEMA No. IC-l, and
NEMA ICS70, National Electrical Code. Refer to Table 25.