Motors & EquipmentQuestion 98 of 120
For that same 20-ampere rated-load compressor supplied alone, what minimum conductor ampacity is required?
a.35 amperes
b.20 amperes
c.25 amperes
d.30 amperes
Explanation
Branch-circuit conductors for a single motor-compressor must have an ampacity of at least 125 percent of the rated-load current or branch-circuit selection current, whichever is greater: 20 x 1.25 = 25 A, which calls for 10 AWG copper. The 35-ampere figure is the 175 percent protective device calculation, and 20 amperes omits the required multiplier entirely.
Law Reference: 2023 NEC §440.32Practice all 120 questions free — no signup required.
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