Electrical – Does big current draw make GFCI outlets go bad


About 2 years ago during a kitchen update, I replaced a GFCI outlet with a new one, 20-amp (both pass through and the GFCI outlet itself). Branching downstream from it are two more outlets, one on the other side of the sink, and one right behind it on the outside of the house. It's an up-to-date "lock" GFCI, is wired correctly and has always tested and functioned correctly. Last week having a new roof put on, the roofers plugged a pretty heavy-duty looking air compressor into the outside outlet. After about an hour, the GFCI tripped. Now, plugging just about anything into the outside outlet is causing it to trip after a few minutes' use, for example yesterday, my shop vac. I have used the shop vac in that outlet many times before with no problem. So, my question is, did the current draw by the air compressor damage the GFCI (it still tests fine). If so, I guess I better replace it.

Best Answer

I have noticed that GFCIs seem to be worn out by heavy, prolonged loads. I can't find any authoritative sources for this effect. Probably the GFCI manufacturers know all about it.

The bridge circuit which detects the flow imbalance depends on some precision electronics which are heat sensitive. The heavy current itself does not affect them, but the side effect of that current heating up the components will lead to premature failure.