3

We bought the house a few months ago.

We have only been able to use 1 burner. If we try to use more than 1 burner, the breaker trips. If we try to use the oven at all, with and without the stove on, the breaker trips. If we reset the breaker, it trips after a few seconds, and it feels warm.

GE JB640SF1SS.

I talked to an appliance guy, he said it the electrical. I talked to an electrician, he said it was the appliance, and to check the wiring on the back of the range. See photos below. Do you think it is the range?

The Breakers do not look burned or damaged when I took the cover off. The circuit is running on two 20A connected breakers. But, when I go to flip the breaker back on, it does feel warm to the touch.enter image description here

9
  • 1
    What size is the breaker? Nov 11, 2021 at 23:38
  • 1
    Two things stand out so far, those burn looking marks on the white thing and the ground(green) wire connected to neutral(white). Ground should be connected to the stove cover/case,like the green wire on top. Those wires connecting to the stove on bottom look small to me, and might mean too small of a breaker.
    – crip659
    Nov 11, 2021 at 23:38
  • 1
    @crip659 , I moved the green ground wire to where it was supposed to be, tried oven again and it broke the circuit in about 2 minutes.
    – Taylor
    Nov 12, 2021 at 0:38
  • 2
    @manassehkatz-Moving2Codidact The oven has a 4 prong 220 with a 50A outlet, running on two connected 20A breakers
    – Taylor
    Nov 12, 2021 at 0:45
  • 1
    @Taylor Never assume, check. Wires might be right size for the breaker now or wrong also. Your breaker seems to wrong size for the stove. People who assume power is off usually get a very nasty surprise. Been there, done that.
    – crip659
    Nov 12, 2021 at 1:08

1 Answer 1

6

The oven has a 4 prong 220 with a 50A outlet, running on two connected 20A breakers

That's the problem. A typical US stove requires anywhere from 30A to 50A. According to the manual for this particular model:

This appliance must be supplied with the proper voltage and frequency, and connected to an individual, properly grounded, 40 amp (minimum) branch circuit protected by a circuit breaker or time-delay fuse.

Which means that under normal usage the stove will use 40 * 0.8 = 32 Amps. Which is a lot more than 20 Amps, so it will trip your breaker pretty quickly. You might think the current is divided equally between the 4 burners and the oven and so parts should work OK as long as you don't use everything at once. But in fact, as you found out, using more than one burner trips the breaker because each burner can use quite a bit of power, as can the oven. The stove will automatically cycle different parts in order to make it all "fit" in 40 Amps (32 Amps continuous) by cycling burners, switching between bake and broil elements, etc. That can be annoying at times ("why is my oven heating up slowly when I have all 4 burners on") but most of the time it all works out OK.

However, the solution is not necessarily as simple as swapping the 20A breaker for a 40A breaker. The breaker needs to protect not just the stove but the wire. The usual sizes are for NM cable (what most people in the US have, outside Chicago) are:

  • 15A = 14 AWG
  • 20A = 12 AWG
  • 30A = 10 AWG
  • 40A = 8 AWG

So if your existing wires between the stove receptacle and the breaker are at least 8 AWG, then you can swap for a 40A double breaker and you should be 100% functional.

If your existing wires are only 10 AWG then you can't use a breaker larger than 30A. And if the 20A breaker is because your wires are only 12 AWG then you are really stuck and can't upsize the breaker at all. 30A/10 AWG is likely enough to get more of your stove working, but definitely not all of it, so that would only be a temporary solution at best. Upgrading the wires is very easy in conduit (which you probably don't have, but we don't know that yet). If you have a cable instead of conduit then it could be anywhere from very easy (kitchen directly above basement electric panel, like my house) to very hard (electric panel on the other side of the house with only finished areas in between).

As far as the 50A receptacle, that is actually quite common because there is no standard 40A receptacle so 50A is specifically allowed as an exception to "receptacle only for one specific size of breaker". (The other exception is 15A receptacles on a 20A breaker.) But there may be another problem with that 50A receptacle. There are two types - NEMA 10 and NEMA 14. NEMA 10 is obsolete because it does not have ground. It is allowed for older installations, but you have a much newer stove. The clue that you likely have a NEMA 10 is that ground is connected to neutral. If you actually have a NEMA 14 plug/receptacle (4 pins instead of 3) then you need to just disconnect the green wire from the white wire and connect the green wire to the metal case instead. If you have NEMA 10 then the ground/neutral connection is correct but ideally you should replace the NEMA 10 with NEMA 14 (and disconnect ground from neutral). Doing that is easy if you actually have ground available at the receptacle. If you don't have ground available and you are upgrading anyway (because you have 10 AWG or 12 AWG wire) then you must replace with NEMA 14 and ground properly. If you don't have ground available and your wires are large enough (8 AWG or larger) then leaving it as-is is not ideal but seems reasonable under the circumstances, though a 50A double GFCI breaker, if available for your panel, would make things quite a bit safer. Based on a comment, it appears that this is a NEMA 14 plug/receptacle and that ground has been moved, but leaving this here as it may be relevant for others in similar situations.

2
  • My suspicion is that the range originally had a 3-wire cord, and it got moved to a residence with a 4 wire outlet and somebody didn't know how to properly connect a 4 wire cord. Nov 12, 2021 at 12:59
  • It could be that. Or it could just have been an improper installation based on past experience ("we always put the green with the white, right?"). Nov 12, 2021 at 13:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.