Equipment & SystemsQuestion 294 of 521
When the Table 430.52 percentage produces a value that does not correspond to a standard fuse or breaker size, NEC 430.52(C)(1) Exception No. 1 permits you to:
a.Round down to the next lower standard size
b.Use the next higher standard size of protective device
c.Double the value
d.Ignore the table and use conductor ampacity
Explanation
430.52(C)(1) Exception No. 1 allows using the next higher standard size when the calculated maximum does not match a standard rating, so the motor can start. Rounding down could cause nuisance tripping; doubling or ignoring the table is not permitted.
Law Reference: 2023 NEC §430.52Practice all 521 questions free — no signup required.
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