Which type of overcurrent protection is required for a 480V, 3-phase feeder in a commercial building according to 240.4(A)?

Texas Master exam practice question · Feeders

Which type of overcurrent protection is required for a 480V, 3-phase feeder in a commercial building according to 240.4(A)?

ASingle-pole fuse
Double-pole fuse
CGround-fault circuit interrupter (GFCI)
DNone, as it is a 3-phase system

Exam tip

Remember that 3-phase systems require double-pole protection.

Why B is correct

According to 240.4(A), a double-pole fuse or circuit breaker is required for a 480V, 3-phase feeder. Single-pole fuses are not suitable for 3-phase systems, and GFCIs are not required for feeders.

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Which type of overcurrent protection is required for a 480V, 3-phase feeder in a commercial building according to 240.4(A)?

Which type of overcurrent protection is required for a 480V, 3-phase feeder in a commercial building according to 240.4(A)?

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