Wire me up for induction, how many amps do I need?

December 9, 2024 7:16 AM

We are planning to switch from gas to an induction stove but don't have a specific model in mind yet. I need advice on the electrical work.

We aren't ready to buy the stove itself yet, but we are having some other unrelated electrical work done in our kitchen soon and I'd like to kill two birds with one stone and get the wiring for the stove done at the same time. My question is, what kind of circuit do I need?

I looked at a few different models and for most of them the spec sheets said that they require a 240V/40A circuit, but one of them said 240V/50A.

I'd prefer to get this taken care of now while I'm having the other work done, as the new circuit for the stove needs to go right in the same place where the other wiring is being done. But since I'm not ready to buy the stove now, I don't really want to choose a specific model and get the wiring done specifically for that, since who knows if that model will still be around when I'm actually ready to buy.

So I guess the big question is, should I go with 40A or 50A? If I went with a 50A circuit and the stove only needed 40A, is that fine? (I assume that it would not work the other way around.) Basically, I want to do the wiring now but of course I don't want to do it wrong and have to pay to have the work redone.

Also, one of the stoves I looked at says the following:

1. Required power supply: 40A
2. Amp rating at 208V: 49A
3. Amp rating at 240V: 49.6A

What does it mean that the 49/49.6A "ratings" are higher than the required power supply?

Any thoughts and advice from people who know more about electricity than I do would be much appreciated, thanks!

posted by number9dream to Home & Garden (14 answers total)

Best answer: I don’t know the answer, but I just read that induction stoves are starting to come with batteries built in that let them use ordinary 120v outlets. The batteries also let them heat higher and faster, work in a blackout, and in one case, even serve as back-up power in a blackout, e.g., for your fridge. They’re thousands of dollars now, but with those advantages and the cost they offset for people who would otherwise need a new subpanel or other wiring work, I’m thinking the landscape might change by the time you get yours. So whatever wiring you put in now may not be what you’d have gone with if you waited until you were buying your stove.
posted by daisyace at 7:48 AM on December 9

Keep in mind that if you're committed to rewiring anyway, you might not have to make a choice. An electrician is going to wire it however current code says it should be wired. If code says a 50amp 240volt circuit, they're not going to have a sit down to discuss your potential range purchases, they're going to install a code-compliant 50amp 240volt circuit. That's one of the great things about the code--it simplifies everything for safety.

One thing you might want to check is if your current outlet has three or four pins. Traditionally electric oven outlets had 3 pins, but having a 4th ground pin increases safety. 3-pin oven outlets are grandfathered because the industry pushed hard against requiring everyone to get their kitchens rewired, but you may want to confirm whether or not new induction stoves can be connected to them.
posted by RonButNotStupid at 8:04 AM on December 9 [2 favorites]

When I upgraded from gas to induction, my previous outlet was 30A and the new stove required 40A, but the local home center only stocked 50A so that's what I went with. Apparently 40A circuits are not very common.

It's completely OK to put a 40A appliance on a 50A circuit, and the cost difference in wiring is minimal. The hardest part is the 50A outlet may require the plug on the 40A appliance to be changed.
posted by jpeacock at 8:35 AM on December 9

Response by poster: Further info in response to what folks have posted already:

Keep in mind that if you're committed to rewiring anyway, you might not have to make a choice. An electrician is going to wire it however current code says it should be wired. If code says a 50amp 240volt circuit, they're not going to have a sit down to discuss your potential range purchases, they're going to install a code-compliant 50amp 240volt circuit.

I've already talked to my electrician and he asked me to tell him what amperage I wanted. He said he could do 40 or 50 amps just depending on what the appliance needed.

One thing you might want to check is if your current outlet has three or four pins.

I currently have a gas stove, so the electricity is only used for the controls and the display etc. It is just a standard three-prong plug on a normal 120V/15A circuit.

About this:

It's completely OK to put a 40A appliance on a 50A circuit, and the cost difference in wiring is minimal. The hardest part is the 50A outlet may require the plug on the 40A appliance to be changed.

How would I go about getting the plug changed? That sounds like a you-just-voided-your-warranty kind of thing...
posted by number9dream at 8:46 AM on December 9

How would I go about getting the plug changed? That sounds like a you-just-voided-your-warranty kind of thing...

Yes and no. Ranges rarely are sold with a cord and plug: the cord and plug are installed on site by whomever is installing the range. However, it is as trivial as taking a screwdriver, and unscrewing 3-4 screws, and then swapping out the plug and re-screwing those 3-4 screws. It is phenomenally easy, but yes, can void your warranty. but again, your range comes delivered with no plug (you often have to pay an additional $10-15 bucks to have it added on, it's annoyingly not even included in the purchase price of your expensive new stove.

I doubt there's a price (maybe measured in a few dollars per part?) with going for a 50a vs a 40a. If you're having work done, future proofing it by going with a 50a would probably be best.

Have the code-compliant, 50a installed- if you get a stove that 'needs' 40a, you'll be fine. The worst case is that the folks installing the range will not have the right cord on hand, and will need to go back to base to get one.
posted by furnace.heart at 8:54 AM on December 9 [2 favorites]

You haven't specified where in the world you live, but those voltages are consistent with what is used in the USA, so I'll make the assumption that you live there. If you do not, be aware that your area may not be the same.

My recommendation would be to have the electrician wire for a 50A circuit. It should be trivial to convert back to a 40A circuit if that is needed.

For a 50A stove circuit, you're going to need a 50A breaker, #6 wire, and either hard-wire to the stove, or use a NEMA 14-50 receptacle (rated for up to 50A).
For a 40A stove circuit, you're going to need a 40A breaker, #8 (or larger) wire, and either hard-wire to the stove, or use a NEMA 14-50 receptacle (rated for up to 50A). (There is no 40A receptacle, so it's the same one as above.)

The cost difference between #8 & #6 wire is going to more-or-less disappear into the labor cost, and there's no safety issue with upsizing the wire from #8 to #6. (American wire sizes are non-intuitive: a smaller number means a physically larger wire.)


Note, however: If the stove manufacturer calls out a max breaker size of 40A, you would need to change out the 50A breaker to a 40A breaker. This would be a simple job for a competent electrician, though if they did not do the job originally, they may want to inspect the original work before they modify it. I'd check with your current electrician to conform that they would be willing to come back and swap out the breaker in the future if you need 40A instead, and that they agree no other work would be necessary for the conversion.
posted by yuwtze at 9:08 AM on December 9 [2 favorites]

Response by poster: Sorry, forgot to include location. I live in Canada.
posted by number9dream at 9:35 AM on December 9

I could almost have asked the same question, currently going through this exact thing (in the UK). I am not an expert but here's what I've figured out so far:

1. As yutwtze highlights; there are actually two related things here: the wire thickness and the breaker fuse rating. The fuse typically protects the wire from overheating - so if you install thinner wire that can only go up to 40A, you can't then put a 50A breaker on it safely; but you _can_ safely put a 40A breaker on thicker wire rated for 50A.

If I went with a 50A circuit and the stove only needed 40A, is that fine?

2. yes this should most likely be fine (as long as the wire is also rated for 50A). The cooker will draw what it needs to draw, and it'll all stay below the breaker/wire limits.

What does it mean that the 49/49.6A "ratings" are higher than the required power supply?

3. I've been confused by this too, my best understanding of it is that the 49/49.6A ratings here are the theoretical maximum current draw if all the heating elements on the range were at full power all the time. This may simply not be possible (i.e. unable to run the broiler + oven element at the same time), or the device may internally limit it's maximum power draw. From what I understand if the manufacturer states the fuse/breaker rating that's the thing you should care about.

Nthing everyone else in this thread, my plan is to just install wire suitable for 50A, and if the cooker I ultimately choose is closer to 40A then all should be fine.
posted by ecstaticcattle at 9:57 AM on December 9

Best answer: In Canada, the 14-50 receptacle is universal, we don't hard-wire or add our own cables like they sometimes do in the US. You probably don't really need 50A as 40A is pretty standard, but I believe it is in fact possible to use 8 AWG for a 50A circuit in Canada, with a compatible receptacle, so you're really only looking at the difference in cost for the breaker, so why not?
posted by ssg at 10:42 AM on December 9

An induction range with 40 amp power will likely plug into a NEMA 14-50 receptacle. The circuit for the appliance should be a dedicated line from the power box, and new conduit may need to be run to the kitchen if the old is rubbish or full/used.

At the power box a circuit breaker will be needed that is rated beyond what the stove will draw. NEC says absolutely no more than 80% so a 50 amp breaker should be sufficient. Your jurisdiction may require either the outlet or the breaker to be GFCI rated to ensure it trips off for safety, and even if they don't I would suggest it's a good idea. The electrician will calculate the size of the wiring as that can vary depending on the length of the run and other factors. I would expect that to be 6 or 8 gauge, and know that long runs of small gauge wire gets expensive quickly.

The electrician will also need to estimate the total load of your household electrical needs and check/judge if the panel or electrical supply needs to be upgraded. A 40 amp appliance is a big draw of power, and an antiquated setup might not be able to handle it. A new panel is lots of work, a new service requires your utility, updating either may require other electrical components to be brought up to code.
posted by zenon at 11:12 AM on December 9

Have the electrician run cables large enough for 50A. It is expensive to change that after the fact, and there is no downside to having slightly oversized wires. But the breaker size and outlet are relatively easy and inexpensive to change later. You could even ask them not to install the breaker yet, and wait until you decide on a stove and know what you'll need.
posted by dbx at 1:56 PM on December 9 [1 favorite]

I just checked, and my electric cooktop (stove is separate) is 240 at only 30amps. I upgraded my panel about 3 years ago, so you should definitely specify what you want, and make sure you get it all at once to save on costs.
posted by The_Vegetables at 3:36 PM on December 9

Absolutely go for 50A service on that breaker no matter what.

Plugs are a different story, but most specification pages for ranges will include a link to the manual for that range. Download it (and the installation manual if it's separate), and use that to determine what kind of plug you'll need.

Here's an example for the LG Studio LSIS6338FE, the top-rated range recommended by Consumer Reports (and they say the cheaper LG LSE4616ST is supposed to perform the same)

Here's one from the Frigidaire Gallery GCFI3060BF, which is the second-highest rated range (and much cheaper).

Both of these say 40/50A for the 30" and 50A for the 36".

So far, I've had two induction ranges and one cooktop. Both ranges required a 50A circuit.
posted by yellowcandy at 7:37 AM on December 10

I'm going from propane to induction/ electric. In Maine, gas lines must be serviced by a certified person. I have an electrician with gas certification coming(in a month). There was an electric stove previously, so the old electric circuit will be used and moved to the current location. We lose power pretty often and my microwave (over the range/ with fan) and stove have both failed - the panel stopped working, auto-ignite broke, and my washer's panel also fritzed out, all in 2 months. So I'm looking in to better surge protection, as well. I plan to get heat pumps, so will check on upgrading the service as needed. It's hard to find an electrician, so I'd rather get it all done at once. Pretty expensive power outages, sheesh.
posted by theora55 at 7:51 PM on December 10