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Trying to be as succinct as possible:

  1. I ordered an induction oven that is rated for 50A and NEMA-50R according to the manual.
  2. I called an electrician and he recommended we install 60A breaker and NEMA-60R receptacle because the oven is pulling nearly 12kW (his logic)
  3. Therefore he wants to change the cord the oven comes with from 50R to 60R NEMA.

Is this dangerous? They've already done the following:

  1. Installed the breaker (60A)
  2. Installed the wire in the wall (6 guage fit for 60A)
  3. Installed the outlet (NEMA-60R)

The oven arrives tomorrow and the electrician is coming to do this last step of changing the cord. But I am having second thoughts (as a non expert non electrician) as my appliance delivery guys were very confused by it.

I've already spent the money and the installation is 90% done so there's no coming back financially, so at this point I need to make a choice. At this point I could tell the electrician to come back, swap out the outlet to NEMA-50R, swap the breaker from 60A to 50A, and not mess with the oven cord. Or I could go with their plan and let them change the oven cord.

My priority is safety at this point. Let me know.

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  • Using larger wires is okay/good. Using a bigger breaker, would need to read the installation manual for what it says about breaker size. The words in the manual are the law. It might say minimum 50 amp or say maximum 50 amp breaker.
    – crip659
    Apr 17 at 18:57
  • @crip659 Thank you for the quick response. I have added a picture from the manual dictating the Amp requirements and receptacle which my electrician is proposing to change, but couldn't get a clear answer. I called LG support and they said 50A is a minimum, but it was their customer support line rather than someone technical. They didn't have any answer about changing the plug configuration.
    – aboose
    Apr 17 at 19:09
  • The wires are okay if they are larger. It is the breaker specs you need. If it says minimum 50 amp breaker it is okay to go with 60 amp breaker if the wires are large enough. If it says maximum 50 amp breaker, then the breaker cannot be larger, but the wires can be. The breaker protects the wires from burning up, so there are minimum allowed wire gauge per size of breaker. Larger sizes are allowed, just they cost more. See what the manual says about breaker size. The three wire/10-50 circuit is only allowed if it was installed before 96. You can plug the stove into it, but you cannot
    – crip659
    Apr 17 at 19:35
  • make/build a new circuit using it.
    – crip659
    Apr 17 at 19:36
  • I for one don't have a problem with it. The lessons we're learning in EV charging is that the amp ratings of 14-50 range outlets are "optimistic". And you always have the defense that you relied on professional advice (a defense I think you'll be seeing in the news a fair bit soon). Apr 17 at 22:51

1 Answer 1

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It seems pretty clear that this is designed for a 50A circuit. There are some special rules regarding ovens, and the manufacturer probably did their best to make this work on a 50A circuit because that is a typical size.

Of course, they probably end up causing some other problems with replacements of older ovens because 40A and 50A circuits use the exact same receptacles, and plenty of people have 40A circuits with 40A/50A receptacles. Those people may blindly plug in their new 50A oven to a circuit that is rated (wire size and breaker size) for 40A and either end up with nuisance breaker trips or more serious problems like fires.

But you have the opposite problem - the electrician wants to oversize things. That is OK for the wire, but not for the breaker. The installation manual clearly says everything needs to be either 40A or 50A, depending on the particular model. Installing a 50A-rated appliance on a 60A circuit risks the small but real possibility of a problem with the oven resulting in an overcurrent situation that is not stopped in time, resulting in damage to the oven. Not likely - there are general multiple levels of protection in oven design - but still possible.

If the electrician insists, contact the manufacturer and get an answer form them. If they say 60A is OK, let the electrician do this. Otherwise, replace the breaker with a 50A breaker and stick with a standard 50A cord/plug.

It also looks to me like this oven can be hardwired, but it is not 100% clear from the manual excerpt. If it can be hardwired then I would:

  • Hardwire with an appropriate cable. Typically that is a "wire whip" rated for 50A, though if rated for 60A that will do no harm.
  • Replace the 60A breaker with a 50A breaker.

That will eliminate a common point of failure with high-current devices - the receptacle. Then you can also tell the electrician: If I get nuisance trips then you can come back and install the 60A breaker, but I'd rather stick with 50A for now. No harm will come from using a 50A breaker on 60A-sized wire. Your electrician is correct that if you use a 60A breaker then you need to use a 60A receptacle and plug/cord, but if you eliminate the receptacle and plug and replace the cord with an appropriate cable then you solve that problem.

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