Motors & EquipmentQuestion 105 of 120
A 20-horsepower, 208-volt three-phase motor has a table full-load current of 59.4 amperes. What is the minimum copper branch-circuit conductor at 75 degrees C terminations?
a.6 AWG
b.4 AWG
c.3 AWG
d.8 AWG
Explanation
The conductor must carry 59.4 x 1.25 = 74.25 A. In the 75 degrees C column, 6 AWG copper is 65 A and falls short, while 4 AWG copper at 85 A is adequate. Choosing 3 AWG is oversized for the minimum, and 8 AWG at 50 A is well below the requirement.
Law Reference: 2023 NEC §430.22Practice all 120 questions free — no signup required.
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