Field answer
Direct answer
A GFCI compares current leaving and returning; shared or crossed neutrals can create an imbalance that trips the device. Use the current equipment manual, code book, employer procedure, and qualified supervision before applying this on live work.
How to use this answer
Read the answer once, then prove it by choosing an answer in a practice question before looking at the explanation. If the miss repeats, tag the domain as GFCI troubleshooting and drill a smaller set before returning to mixed practice.
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