Kitchen range 40 or 50 amp?

[dhalleron]

I was so used to always installing a 50 amp circuit years ago. I have to give a guy a price on adding a circuit to a 2nd floor kitchen. He does not have the range and might not be buying it himself.

Do many modern residential ranges need a 50 amp circuit or will 40 do? I want to save the guy some money since he will be selling this house once he fixes it up, but I don't want to put in something that might be undersized either.

A quick look at a few different spec sheets for ranges on Home Depot's website shows 40 amps.

 

[Strife]

Why does it matter?
You need #8 for either scenario.
And I don't think they make a 40A receptacle/plug either.
And BTW 2P40A breaker cost just as much as a 2P50.

I was so used to always installing a 50 amp circuit years ago. I have to give a guy a price on adding a circuit to a 2nd floor kitchen. He does not have the range and might not be buying it himself.

Do many modern residential ranges need a 50 amp circuit or will 40 do? I want to save the guy some money since he will be selling this house once he fixes it up, but I don't want to put in something that might be undersized either.

A quick look at a few different spec sheets for ranges on Home Depot's website shows 40 amps.

 

[Dennis Alwon]

The standard ranges generally take 40 amps but nothing seems to be standard anymore. I have done many that take 50 amps.

 

[Hv&Lv]

Why does it matter?
You need #8 for either scenario.
And I don't think they make a 40A receptacle/plug either.
And BTW 2P40A breaker cost just as much as a 2P50.

Quite right. 30,50,or 60, but no 40...

 

[svh19044]

Most of the Wolf electric range/oven appliances call for 50 amp. You aren't saving much money by downsizing to a 40amp (if you go with 6/3 instead of 8/3 romex, you are talking $40 assuming you use a full 125' roll, other additional expenses are non-existent), so in the scope of the job, it's impact seems minimal and questionable.

The standard ranges generally take 40 amps but nothing seems to be standard anymore. I have done many that take 50 amps.

...like the range receptacle location. :rant:

 

[infinity]

Why does it matter?
You need #8 for either scenario.
And I don't think they make a 40A receptacle/plug either.
And BTW 2P40A breaker cost just as much as a 2P50.

With NM cable you would need larger than #8 conductors for a 50 amp circuit vs. a 40 amp.

 

[kwired]

40 amps @ 240 volts is 9.6kW. Many ranges are 12kW or so, some even more.

The reason you can put them on a 40 amp breaker is that they never draw more than that, and if they do it is not for long enough time to trip the breaker. Heat elements cycle on and off as needed to maintain temperatures - they do not run continuously when it is on.

If you were only using one surface element you could put it on a 15 amp breaker and never trip it. You may even be able to use two surface elements on a 15 amp breaker in many cases.

 

[Sierrasparky]

I'm not so sure about this. If you look at 210,19 C

(3) Household Ranges and Cooking Appliances. Branchcircuit
conductors supplying household ranges, wallmounted
ovens, counter-mounted cooking units, and other
household cooking appliances shall have an ampacity not
less than the rating of the branch circuit and not less than the
maximum load to be served. For ranges of 83/4 kW or more
rating, the minimum branch-circuit rating shall be 40
amperes.

Says you can use any range 83/4 or more on a 40 amp.. I guess just go with #8 thhn or #8 NM and be good!:happyyes:

 

[dhalleron]

Thanks all for your input.

 

[hillbilly1]

I put in a double oven a while back, the nameplate KW required that I use a 50 amp breaker, but the manufacture called for a 40 amp.

 

[ptonsparky]

I can't remember using more than a 40 amp breaker for any range. But then again I don't always remember what I was doing two hours ago. On new homes I rarely saw the range until final walk through let alone knew the KW of it ahead of time.

 

[kwired]

40 amps @ 240 volts is 9.6kW. Many ranges are 12kW or so, some even more.

The reason you can put them on a 40 amp breaker is that they never draw more than that, and if they do it is not for long enough time to trip the breaker. Heat elements cycle on and off as needed to maintain temperatures - they do not run continuously when it is on.

If you were only using one surface element you could put it on a 15 amp breaker and never trip it. You may even be able to use two surface elements on a 15 amp breaker in many cases.

I'm not so sure about this. If you look at 210,19 C

(3) Household Ranges and Cooking Appliances. Branchcircuit
conductors supplying household ranges, wallmounted
ovens, counter-mounted cooking units, and other
household cooking appliances shall have an ampacity not
less than the rating of the branch circuit and not less than the
maximum load to be served. For ranges of 83/4 kW or more
rating, the minimum branch-circuit rating shall be 40
amperes.

Says you can use any range 83/4 or more on a 40 amp.. I guess just go with #8 thhn or #8 NM and be good!:happyyes:

Was that a response to what I said about the 15 amp breaker? I was not suggesting that somebody install a 15 amp breaker I was only pointing out that when using only one or two surface elements (which I think happens a lot, it does at our house) the thing does not draw that much load. Start using more than that you will need a larger circuit, but you also do not need a circuit sized for largest possible load because the diversity of the load does not get that high - at least not for long enough time to be a problem.

 

[bradleyelectric]

Was that a response to what I said about the 15 amp breaker? I was not suggesting that somebody install a 15 amp breaker I was only pointing out that when using only one or two surface elements (which I think happens a lot, it does at our house) the thing does not draw that much load. Start using more than that you will need a larger circuit, but you also do not need a circuit sized for largest possible load because the diversity of the load does not get that high - at least not for long enough time to be a problem.

I think it was a response to the OP

 

[infinity]

I put in a double oven a while back, the nameplate KW required that I use a 50 amp breaker, but the manufacture called for a 40 amp.

When sizing the range branch circuit you can use the demand factors in T220.55. A single 12 KW range will have a maximum demand of 8KW. 8000/240=33.3 amps. 40 amp circuit is fine.