National Electrical Installation Standards

Standards as High as Your Own

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Friday, July 3, 2020

Question:

Hello Electrical Team,

Where does the NEC say I have to test my wiring for insulation integrity before energizing circuits?

Harold Furman

A

Answer:

Greetings Harold and thanks for the question. The NEC does not say that directly. However, there is a rule (Section 110.7) that requires that completed wiring installations be free from short circuits and ground faults or any connections to ground other than those required or permitted elsewhere in the NEC. To verify compliance with this rule, a test instrument is typically used to verify and confirm there are no short circuits or ground faults prior to energizing. Other standards may also require specific testing prior to energizing circuits or equipment. 

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IMPORTANT NOTICE: Unless the question requests a response based on a specific edition, all answers are based on the latest edition of NFPA 70® National Electrical Code®.

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