Our house is 3 years old. We have an electric kettle which had developed some scale build up that I wanted to clean. I put about half a cup of vinegar in it and filled it the rest of the way with water, plugged it into the same outlet I always use, a GFI-protected outlet on the backsplash. I turned the kettle on and let it come almost to a boil, then turned it off and unplugged it.
About 5-10 minutes later I was sitting in the living room and heard a loud buzz from the kitchen that lasted 5-10 seconds. It sounded like hair clippers trying to cut through sheet metal. I rushed into the kitchen and identified the source of the sound as the GFI outlet. Then, when I was wondering if I should push the reset button, the outlet sparked and a bit of acrid smoke wafted out. I went to the breaker box to throw the breaker, but it was already tripped.
So, what happened? Did the vinegar contribute in any way?
I have no clue what could have caused something like that, but I do know that any situation involving smoke coming out of an electrical outlet is something that you really need to call a professional electrician about. Like, right this moment. Before your house burns down or something.
keep that circuit breaker off until the GFI-protected outlet is replaced and the problem for the circuit breaker being tripped (which likely was the GFI-protected outlet dying) is corrected.
One thing I forgot to mention is that when I unplugged the kettle, the plug (not the outlet), was warm, which is why I thought it might be the kettle itself pulling too much current or something.
those kettles draw a lot of current. it is not unusual for you to feel some warmth. as the cord/plug deteriorates it will also keep feeling warmer until it breaks totally. if a plug or cord ever feels more than warm replace the cord/plug/appliance.
in your case since the GFI outlet was smoking 10 minutes after you unplugged the kettle then the GFI outlet is toast.
I do not think the kettle itself or its plug is the problem. Likely it was the act of plugging/unplugging it that was the final straw for the GFCI. There is probably a loose wire with a small gap between hot/neutral. This could be in the GFCI or in the wiring in the box behind it. You had a bunch of sparking which eventually tripped the breaker.
You will need to replace the GFCI, and also check all the wires in the receptacle box for worn insulation. It could be something like the GFCI is not solidly screwed in and wiggles when you plug unplug it. If a hot wire is pressed against a sharp piece of grounded metal, every plug/unplug could be wearing down the insulation. Wherever the problem originated you will likely see blackened scaring around the short.
I’d also check that the wire itself (the copper) looks OK. I had a loose connection in a dryer that caused the wire to heat up and, I don’t know, get brittle? look enameled? from the heat.
Anyway, I had to cut back a couple inches to get to wire that seemed “fresh”.
Eh, I wouldn’t be surprised if the kettle was what triggered everything. I’m guessing a bit here, but I suspect that the kettle was drawing a lot of current, maybe even a bit too much current, and this caused the GFCI to fail. This probably means that the GFCI was already damaged and was going to fail at some point anyway, and the extra stress of all of that current pushed it over the edge and made it go.
The breaker seems to have tripped as a result of the GFCI shorting out and dying a spectacular death. The kettle drew enough current to make the plug get hot, but it didn’t draw enough current to trip the breaker. It may be that the heating element in the kettle is starting to go south and it’s drawing more current than it should.
You definitely need a new GFCI. You may need a new kettle when all is said and done as well.
The wiring around the GFCI also needs to be examined for damage. (ETA: I see now that this was already mentioned)
Electric kettles are used for a minute or so at most. Not likely that the heating element would fail, is it? My mother has one that’s thirty years old.
Heating elements are pretty simple things. There are a few different styles and a few different materials that they make them out of, but they are all basically fairly simple resistors. They aren’t likely to fail, but it does happen on occasion. It’s fairly common for them to last for decades, as your mother’s has. On the other hand, the OP did mention scale buildup in the kettle so this isn’t a new kettle. There could be corrosion in the heating element or some other type of damage present.
Actually, it’s only a couple of years old. We have really hard water so there was getting to be a little bit of buildup on it, but not so that it looked visibly corroded. Just some specks that were dulling there surface, and the vinegar was an experiment/proof of concept to see if it would make it shiny again.
The kettle draws quite a bit of current. There was a high resistance connection somewhere inside the GFI. Likely culprits include:
Plug/receptacle contact (where the prongs on the plug make contact with the spring terminals inside the GFI).
Rely contact (a relay is located inside GFI).
Screw terminal (a loose screw terminal where the hot & neutral wire connects to the GFI).
The I[sup]2[/sup]R heat from the poor connection became a glowing contact, and the heat conducted along the conductors inside the GFI. This degraded/melted the insulation adjacent to the conductors, especially insulation made of thermoplastic such as PVC. Arcing ensued, causing a short and tripping the breaker.
Check the prongs on the power plug attached to the kettle’s power cord. Do you see any evidence of discoloration, pitting, or missing material?
A couple more questions:
Are there any other 120 VAC receptacles connected to the load side of this GFI?