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Here’s my deep dive on GFCI theory.

https://rvelectricity.substack.com/p/noshockzone-on-gfci-theory

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Mike, I can't figure out your explanation. It's my understanding that a GFCI detects faults which cause currents to flow in the Ground line. Why would mixing the Neutral currents in the Y adapter cause any sort of Ground fault? What am I missing?

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Greg, GFCI receptacles don’t need the ground wire to work properly. They are only looking for an imbalance between the outgoing current and the returning current.

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Apr 15Liked by Mike Sokol

My understanding is that a GFCI compares line current flow to neutral current flow. That is why an unground appliance, like a kitchen toaster can trip a GFCI when line and neutral current flows do not match each other. When neutral current flow going through the GFCI neutral is causing a mismatch to line current flow of the GFCI, because neutral currents are also flowing through the 30 amp plug neutral, the GFCI trips. Current flow in the GFCI ground should also trip it, however ground current flow is not necessary to trip a GFCI.

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Well James, that does seem like a reasonable explanation. I guess I took the "GF" part of GFCI too literally (ground fault). I did some quick research, and indeed the GFCI does not specifically check for ground current; instead, it checks for equality of hot/neutral. Apparently, the assumption is made that if those currents aren't equal, the offset has gone to ground.... ergo "ground fault". Thanks for the reply.

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I tried the 45amp Y adapter one time. It tripped the breaker on the pedestal. I never tried again. I just monitor my usage.

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