When grounding exposed non-current-carrying metal parts of motors and controller frames to prevent a voltage above ground in the event of accidental contact between energized parts and frames, what are suitable alternatives to grounding of motors under certain conditions?
A) Insulation
B) Isolation
C) Guarding
D) All of the above
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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. 430.241, “Part XIII specifies the grounding of exposed non-current-carrying metal parts, likely to become energized, of motor and controller frames to prevent a voltage aboveground in the event of accidental contact between energized parts and frames. Insulation, isolation, or guarding are suitable alternatives to grounding of motors under certain conditions.”
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].