Q. What is the proper size branch-circuit, short-circuit, ground-fault protective device required for a hermetic compressor with a nameplate rated load of 38A? The branch-circuit selection current on the nameplate is rated at 40A. Note: Do not exceed the values obtained from the lower multiplier.
Explanation: As per 440.22 of the 2005 NEC, you must use a multiplier of 1.75 (175%) for this calculation.
40A x 1.75 = 70A
A check of 240.6 reveals that 70A is a standard size ampere rating for fuses and inverse time circuit breakers.
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