Microwave Keeps Tripping the breaker

[eblend]

Hi guys,

So I have an IKEA wall mount microwave and the instructions say it will work on a 15 or 20 AMP circuit. In my case I have a dedicated 15AMP circuit, but every once in a while, it will trip. Usually this happens when we are using a "Pasta Boat" to cook pasta, the microwave is set to run for like 14-16 minutes, but about half way through cuts out. I have to go to the basement, reset the breaker, and it finishes the job. This is obviously annoying, and I am trying to figure out why. Is it the microwave...house wiring, or specific situation. When we do the noodles there is a lot of steam inside the microwave and the glass fogs up, which makes me think this is related. Anyone have any insight? I have warranty on the item but don't want to call them until I have more information. Day to day use for warming up meals it's perfectly fine, but anytime it runs for a long period of time and lots of steam, it trips.

[BerserkerCatSplat]

You could use something like a kill-a-watt to see how much power it's actually drawing. The rated wattage should be marked on the unit or in the manual, divide watts by 120V to get rated max amperage draw - if it's pulling more than that it's a faulty unit. Try the unit on a different dedicated circuit (like in the garage) and see if the same thing happens - if it doesn't (assuming your dedicated microwave circuit is indeed dedicated and has no other loads) it may be a faulty breaker.

[revelations]

+1 on a faulty breaker.

[01RedDX]

.

[ThePenIsMightier]

It's a kitchen, so aren't GFI outlets code?
*Looks and realizes mine aren't... WtF?! Maybe that's a BC thing?
Is it tripping that, or the breaker in the panel?

[littledan]

If your home is relatively new construction its probably an arc-fault breaker. The microwave can trick the breaker into thinking there is a fault. Running your micro at a slightly lower power may reduce the frequency of it tripping. On my micro at home I usually run it at 80% and it wont trip at that level

[eblend]

Thanks guys. That Kill-a-watt thing could be useful as I have been using my UPS with LCD screen to test load on some equipment, so I can see it being put to use in the future and worth an investment. Do they have a battery which shows the peak load reached...or does it die when the breaker trips? I have to install it in the back where I can't see the display, or the plug for that matter.

Didn't realize breakers can go bad. I got a bunch of new ones when I built my basement, so I can try swapping one out and see if it fixes that problem. The breaker in the basement is labeled Microware and it's a dedicated circuit just for the microwave. House built in 2006 and it's just a standard breaker, no GFI or arc-fault.

[Tik-Tok]

Try tightening the screws on the breaker first. We had a similar issue, and I found mine had backed off a hair over time.

[BerserkerCatSplat]

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It's a kitchen, so aren't GFI outlets code?
*Looks and realizes mine aren't... WtF?! Maybe that's a BC thing?
Is it tripping that, or the breaker in the panel?

It is code now for outlets near the sink, but that's a somewhat recent change IIRC. Individual non-GFCI 15A plugs in the kitchen were code for ages.

[ExtraSlow]

Easiest way to figure out if anything else is on that breaker is to leave it turned off for a day.

Does sound like a weak breaker though, as it can heat up with longer uses.

[BerserkerCatSplat]

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Thanks guys. That Kill-a-watt thing could be useful as I have been using my UPS with LCD screen to test load on some equipment, so I can see it being put to use in the future and worth an investment. Do they have a battery which shows the peak load reached...or does it die when the breaker trips? I have to install it in the back where I can't see the display, or the plug for that matter.

Temporarily run a 15A extension cord from the microwave outlet and plug the Kill-A-Watt/microwave into the cord, should be able to see it that way and the cord won't affect amperage draw..

[hrdkore]

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It is code now for outlets near the sink, but that's a somewhat recent change IIRC. Individual non-GFCI 15A plugs in the kitchen were code for ages.

it's code for GFCI outlets if they are within 1.5m of a sink, but not required for dedicated equipment with designated space.

If you want to troubleshoot, plug the microwave into another kitchen receptacle and make sure no other devices are plugged it or lights on and try heating pasta again. If it trips, its the microwave.

[ThePenIsMightier]

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it's code for GFCI outlets if they are within 1.5m of a sink, but not required for dedicated equipment with designated space.

If you want to troubleshoot, plug the microwave into another kitchen receptacle and make sure no other devices are plugged it or lights on and try heating pasta again. If it trips, its the microwave.

It's a wall mounted microwave, so that's a bit more difficult.

[eblend]

Update to the thread. Last week before a week long Denver work trip, I swapped out the old breaker for one of the new ones I installed when doing my basement development. My wife used the microwave for the whole week, including cooking the pasta, and again today we ran it for 17 minutes making pasta, and it no longer trips! Thanks guys. I didn't even know that faulty breakers are a thing, now i do!

Thanks, all is resolved.

EDIT: I did pickup a Killawatt while in Denver, much cheaper there even with the exchange rate, will be useful for other things around the house.