Question 13096 of 790 · California General Electrician Exam
A feeder supplies three 460 volt motors: 25 hp (34 A) protected by a 90 A inverse time breaker, 15 hp (21 A) and 10 hp (14 A). What is the maximum rating of the feeder overcurrent device?
Exactly one answer is correct.
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Correct answer to question 13096
- D: 125 A
Explanation
The feeder device may not exceed the largest branch-circuit short-circuit and ground-fault device plus the sum of the other motors' full-load currents: 90 + 21 + 14 = 125 A. Since 125 A is a standard size it may be used, and rounding up to 150 A is not permitted for feeders.
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