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We have three outlets in our kitchen that are all connected to one circuit breaker. We often use these outlets for our toaster oven and rice cooker. About a month ago, the outlet started to trip the GFCI + circuit breaker whenever we used our toaster oven or rice cooker. I initially thought this might be due to a bad GFCI in one of the outlets, so I replaced all three (bought pretty expensive $25 outlets thinking that this would hopefully solve the issue).

We started to use the outlets again with the rice cooker and toaster oven. Everything was fine for about a week with everyday use. Then the same thing started to happen again

We remodel our home 2 years ago with all updated electrical except for the panel outside (it had been updated in the last 5 years).

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    I take it the GFCI is a receptacle-type unit, correct? Also, does the breaker have a TEST button on it, and what make and model is it for that matter? – ThreePhaseEel Nov 11 '18 at 3:29
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    Do you have three receptacles on one circuit in the kitchen? Do you have three GFCI receptacles on the same circuit? This can be a legitimate (but more costly) use of GFCI receptacles, but most people just use one GFCI receptacle on the first receptacle and use the load terminals to feed the downstream receptacles. What you don't want in general is to use multiple GFCI receptacles on the same circuit AND use the load terminals. Also you don't want to use ANY GFCI receptacles on a circuit fed by a GFCI breaker. – Jim Stewart Nov 11 '18 at 11:25
  • ThreePhaseEel--Yes, these were receptacle-type GFCI unites. The breaker on the panel does not have a test button on it. The breaker is a Square D. – Laserguy Nov 12 '18 at 5:36
  • Jim--Yes, I have three GFCI receptacles on one circuit in the kitchen. I put them in basically because the guy who did the electricals in my house had originally done it that way. The breaker outside isn't a GFCI breaker. Could putting multiple GFCI receptacles on the same circuit be the issue? As far as I can tell, all the outlets in my kitchen are GFCI receptacles. – Laserguy Nov 12 '18 at 5:42
  • Laserguy - be sure to understand the subtlety of Jim Stewart's comment - he's asking if the GFCI outlets are wired in a daisy-chain fashion: one's load terminals are feeding the next GFCI – mike65535 Nov 12 '18 at 15:21
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The reason people think multiple GFCIs is odd, is this: A GFCI device (receptacle, deadfront or breaker) can protect additional outlets beyond itself. This is done by using the LOAD terminals. On a GFCI deadfront or breaker, using those terminals is essential. However on a GFCI receptacle device, the LOAD terminals are a constant source of misconfiguration by novices, handymen, ahem drywallers etc. Either they miswire it so it constantly trips, or they accidentally GFCI-protect outlets they were not expecting to, resulting in nuisance trips and surprise outages. So there is a warning tape across the terminals, that says in as many words, "Do Not Use: For Wizards Only".

Don't get me wrong, in a perfect world everything would be GFCI protected and every load that trips a GFCI would be fixed, and technical acumen and money would flow unlimited to get this done. However, in reality the technical acumen or time just isn't there, and the dangling problem isn't particularly serious. Compromises must be made.

So... multiple GFCIs on a circuit are appropriate when the installer realizes he is not a wizard; or; when there are downline loads which should not be GFCI protected for one reason or another. There's no way to protect half a downline. The apocryphal example is where receptacles are wired panel-1-2-3-4, with countertop receptacles in 1-2-3 and a refrigerator is plugged into 4 and it trips GFCIs. I don't care: A grounded refrigerator is the exact opposite of the use case for a GFCI, being a grounded metal box with all the electrical bits in the bottom back, shielded and beyond arm's reach for a human, and you are unlikely to drop a refrigerator in the sink.

In such a case, the LOAD terminals will not be used at all.

Your direct problem

First you need to test. Since your devices are tripping both the Breaker (which looks for excessive current hot-neutral or hot-ground) and the GFCI (which looks for any current other than hot-neutral), the common factor is hot-ground, and current must be very high (bolted). An ohmmeter should measure this resistance out at near zero, and it would trip a plain breaker on any circuit. By the way, for that to happen, the appliance would need to have 3-prong sockets. If 2-prong, don't bother with this test:

I would first measure hot-ground with an ohmmeter and look for numbers that are too low (less than 5 ohms). Then try them on other circuits, particularly a non-GFCI such as the electrician's socket (if present) at your electrical panel since it's least likely to break anything else. Also, I would try it in your bathroom's GFCI. If it fails there, it's the appliances. If it does not fail...

I think your problem is one of two things: either the LOAD terminals were in fact used, and misused; or more likely you have a grounded metal box and the wire attachment screws of the GFCI (perhaps the LOAD neutral screw) is touching the metal box. If the back connections were used and the wire is pulling out of the back connections and touching the metal box, I've had that happen. Maybe it happpens when you plug the appliance in because you are flexing the box. Regardless, make a few wraps of electrical tape around the GFCI to cover the side screws. That is a good practice on any receptacle.

  • "you are unlikely to drop a refrigerator in the sink". Thanks, I needed that laugh! – FreeMan Nov 14 '18 at 21:00

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