For my remodel I replaced the somewhat inadequate single outlet in our kitchen with a pair of outlet circuits per code. There is a GFI-protected outlet at the beginning of each series along the countertop and yet I recently tripped the breaker at the service panel for one of them. I know they have to be wired in series and I know there is a correct line and load connection for the receptacles when they are installed and I’m certain I did it right.
That said, how can I be tripping the breaker at the panel instead of the GFI doohicky first? This has happened twice now? I’m not feeling very protected. Any clues?
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The GFCI and breaker are looking for different things. (layman's explanation) The GF specifically looks for current finding any other path besides neutral, like if you had your hand on the water faucet and a faulty appliance at the same time, the breaker senses heat, shorts to ground, or shorts to neutral.
Are these 20 amp circuits? What was going on when the breaker tripped?
Okay. I think I get it now. The curcuits are 20 amp. I was drilling though a particularly dense old stud when I blew it (kitchen isn't completely done yet) that's actually surprising too. The drill was certainly working, but 20 amps worth? Anyway. Thanks. It makes more sense to me now.
This is entirely reasonable. The GFI senses "ground faults"; i.e., current going to ground rather than to the neutral (which could be bad because it means the current could be going through you on the way to the ground).
The breaker senses overcurrent; i.e., the current's going to the neutral properly, but there's so much of it that the wires are in danger of getting too hot. 'different problem from the GFI.
My wife blows a kitchen breaker when she forgetsanf tries to run the toaster oven and the deep fryer on the same circuit. But the GFI doesn't trip.
I'd assume you wired each half of the outlet string to a leg on a 220VAC 20 Amp breaker. Either you have a defective breaker, or you are drawing more then 20 Amps on one leg of the breaker.
Do you happen to have the toaster and microwave plugged into the same circuit? Or some other combination of high drawing appliances? One warning, a fridge or freezer shouldn't be on a GFI circuit, if it is change it. Also, most new houses put the microwave on its own circuit, this can avoid nuisance trips.
The way kitchen outlets are typically wired, you have 40 Amps available power, but the way 220 breakers work if either leg exceeds 20 Amps, it trips the breaker shutting off power to both sides of the outlet.
The GFI issue has been dealt with, if you're nervous, use the test button on the outlet. If you're still nervous, buy a plug in GFI tester and test it with that.