Motors & EquipmentQuestion 91 of 120
For that same two-motor feeder, if the largest branch-circuit protective device is 90 amperes, what is the maximum feeder overcurrent device rating?
a.90 amperes
b.104 amperes
c.110 amperes
d.100 amperes
Explanation
The feeder device may not exceed the largest branch-circuit short-circuit and ground-fault protective device plus the sum of the full-load currents of the other motors: 90 + 14 = 104 A. Since 104 is not a standard rating and this is a maximum rather than a minimum, the next lower standard size of 100 amperes must be selected. Choosing 110 amperes would exceed the calculated ceiling.
Law Reference: 2023 NEC §430.62(A)Practice all 120 questions free — no signup required.
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