Question 13014 of 790 · California General Electrician Exam
A three-phase 460 volt motor delivers 25 hp with an efficiency of 92 % and a power factor of 0.86. What is the actual line current (not the NEC table value)?
Exactly one answer is correct.
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Correct answer to question 13014
- B: 29.6 A
Explanation
Input power is 25 x 746 / 0.92 = 20,272 W, and I = P / (E x 1.732 x PF) = 20,272 / (460 x 1.732 x 0.86) = 29.6 A. Ignoring both efficiency and power factor gives 23.4 A; forgetting 1.732 gives 51.2 A.
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