Adding an oven load to existing panel

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Ferbstorm

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Oregon
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Journeyman Electrician
Hello. I'm an electrician who works primarily in commercial and industrial stuff, so I have completely forgotten how to do these calculations. A friend is asking me for a little guidance on his home remodel, and I just want to make sure he stays safe.

He's replacing a gas stove with two electrical appliances. They add up to 49A and operate off 240v. But because he doesn't have an electric stove already it's adding a load, not just replacing it. He doesn't have access to his main breaker (has to contact building maintenance for that) but when we do have that information, how would I go about verifying that he's not about to overload his panel? I wasn't stellar at these calculations when I was in the apprenticeship, and haven't had to touch them in years.

His panel at the moment has
(3) 2-pole 30A breakers
(1) 2-pole 15A
(4) 1-pole 15A
(3) 1-pole 20A

The new stove will be a 2-pole 60A

Also the 2p 15A and one of the 2p 30A breakers are both in floor heating that he's prepared to ditch if he needs to, as he barely uses it to begin with, so that is an option.

Thanks in advance for any assistance provided
 
Ferbstorm said:
Hello. I'm an electrician who works primarily in commercial and industrial stuff, so I have completely forgotten how to do these calculations. A friend is asking me for a little guidance on his home remodel, and I just want to make sure he stays safe.

He's replacing a gas stove with two electrical appliances. They add up to 49A and operate off 240v. But because he doesn't have an electric stove already it's adding a load, not just replacing it. He doesn't have access to his main breaker (has to contact building maintenance for that) but when we do have that information, how would I go about verifying that he's not about to overload his panel? I wasn't stellar at these calculations when I was in the apprenticeship, and haven't had to touch them in years.

His panel at the moment has
(3) 2-pole 30A breakers
(1) 2-pole 15A
(4) 1-pole 15A
(3) 1-pole 20A

The new stove will be a 2-pole 60A

Also the 2p 15A and one of the 2p 30A breakers are both in floor heating that he's prepared to ditch if he needs to, as he barely uses it to begin with, so that is an option.

Thanks in advance for any assistance provided
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The number and size of the breakers has nothing to do with what loads can be added. You need to do a load calculation. Article 220 is where you will find load calculations. Article 220.83 is for existing loads. That is where you need to start.
Also, most stoves only use a 40A breaker unless it has extra features from a normal stove.
 
Little Bill said:
The number and size of the breakers has nothing to do with what loads can be added. You need to do a load calculation. Article 220 is where you will find load calculations. Article 220.83 is for existing loads. That is where you need to start.
Also, most stoves only use a 40A breaker unless it has extra features from a normal stove.
Click to expand...
Awesome, thanks for the fast reply! So the stove/oven appliances have a combined faceplate rating of 49A. He's opting for a 60A breaker and wire cause he doesn't want to squeak in under the limit. So just to be clear, I'd calculate the VA already accounted for according to 220.83, then just add in the new oven divide by 220v, and make sure the main breaker exceeds the number I get afterwards? Just wanna be extra clear since I'm not uber familiar with this
 
Ferbstorm said:
Awesome, thanks for the fast reply! So the stove/oven appliances have a combined faceplate rating of 49A. He's opting for a 60A breaker and wire cause he doesn't want to squeak in under the limit. So just to be clear, I'd calculate the VA already accounted for according to 220.83, then just add in the new oven divide by 220v, and make sure the main breaker exceeds the number I get afterwards? Just wanna be extra clear since I'm not uber familiar with this
Click to expand...
Yes, if you did the calculations on what is existing. You divide by 240V not 220V.
 
You mention that he is adding 2 appliances. Powering them both from a single 60A branch circuit might not be code-compliant, especially if one or both is cord and plug connected.
 
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