W-C-375-SUP-2 Circuit Breakers, Molded Case; Branch Circuit and ServiceThis specification covers the general requirements and test procedures for molded case circuit breakers which fall within the general parameters specified in table XVI which are specifically designed to provide service-entrance, feeder, meter-service, or branch circuit protection and rated at not more than 4,000 amperes and 600 volts ac, 60 hertz Hz see 3.1 and 6.1.

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W-C-375E

3.4.10  Terminals.  Unless otherwise specified (see 3.1), the line terminals of a circuit breaker rated at 40 amperes or less shall be capable of accommodating No. 8 AWG conductors.

3.4.11  Multi-pole circuit breakers.  A multi-pole circuit breaker (having two or more poles controlled by a single, manually operated actuating member) shall be so designed that all poles will make and break simultaneously when operated manually or automatically in the intended manner; except that in a two- or three-wire circuit breaker rated at

120/240 volts or less and having two operating poles designed for use on the outside (ungrounded) wires of a three- wire, single-phase alternating current system having a solid neutral, the automatic tripping of either pole may be

independent of the other, provided that the independent tripping is indicated.

3.4.12  Interlock.  If fused circuit breaker current limiters or fuses are housed within the circuit-breaker frame, the circuit breaker shall be so interlocked that when the cover over the limiters or fuses, or the limiter pack, is removed, the circuit breaker will automatically trip.

3.4.13  Multi-limiter characteristics.  If fused circuit breakers are designed to use two or more current limiters with different let-thru characteristics for different ranges of ratings within a frame size, it shall be difficult to install a limiter in any lower rated circuit breaker where it is not intended, if such installation could result in a hazard.

3.4.14  Trip indication on limiter opening.  Fused circuit breakers shall be so designed that opening of the limiter or fuse will trip the circuit breaker mechanism.

3.4.15  Accessories.  Accessories shall be in accordance with the applicable requirements of UL 489.

3.4.16  Spacings.  The spacings between circuit breaker components shall be not less than those indicated in

table I..  Soldering lugs or pressure wire connectors shall be prevented from turning so as not to reduce the spacings specified, except that if such minimum or greater spacings are maintained when lugs are turned 30 degrees toward

each other or toward other uninsulated live or grounded parts, no means to prevent turning need be provided.

TABLE I.  Minimum spacings.

1/  The spacing to the enclosure or circuit breaker mounting means may be reduced if an acceptable liner of insulating material, not less than .031 inch (0.79 mm) in thickness, is used to provide the required spacing through air.

2/  If indentation or deformation of the overall enclosure or circuit breaker mounting means may reduce spacings to less than those indicated in column E.

3/  If indentation or deformation of the overall enclosure or circuit breaker mounting means will not affect

spacings.

3.4.17  Standard ampere ratings.  Standard ampere ratings for circuit breakers are 10, 15, 20, 25, 30, 35, 40, 45,

50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1,000, 1,200,

1,600, 2,000, 2,500, 3,000, and 4,000 amperes.

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