Code Quiz: Motor Controller Grounding Requirements

Feb. 22, 2018
NEC Rules on Motor Controller Grounding Requirements, controller enclosures

Excluding exceptions, motor controller enclosures shall be connected to the equipment grounding conductor (EGC) ______________. Controllers shall have a means for attachment of an EGC termination in accordance with ____________.

A) Every time / the manufacturer’s instructions
B) Only for grounded systems / the engineer’s specifications
C) Only for ungrounded systems / NEC Sec. 250.66
D) Regardless of the voltage / NEC Sec. 250.8

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Answer: D

Article 430 of the 2017 NEC focuses on motors, motor circuits and controllers. Part XIII of this Article covers the grounding requirements for all voltages. As per Sec. 430.244 (excluding the exception), “Controller enclosures shall be connected to the equipment grounding conductor regardless of the voltage. Controller enclosures shall have a means for attachment for an equipment grounding conductor termination in accordance with 250.8.”

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at [email protected].

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