Range "Oven"

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carloslt

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Electrician
I am working with old houses with old breaker boxes and can not find a replacement breaker. If I hardwire a "RANGE" with a #6 awg wires and a 70 amp Breaker protection. Am I in violation of the "National Electric code"?
 
You could take the 70A breaker and feed a disconnect that holds a singe 2 pole breaker and put a 40 or 50 amp breaker in the disconnect. More expensive but safer then feeding the stove with a 70 amp circuit.
I would think supplying a 40 or 50 amp device from a 70a circuit would violate code.
 
Rock86 said:
I'm a little surprised it took 5 posts to catch that.
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#6 AWG, THHN wire has an ampacity of 75 amp. It is more than enough for the breaker.
robertd said:
You could take the 70A breaker and feed a disconnect that holds a singe 2 pole breaker and put a 40 or 50 amp breaker in the disconnect. More expensive but safer then feeding the stove with a 70 amp circuit.
I would think supplying a 40 or 50 amp device from a 70a circuit would violate code.
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I think, safety is not an issue. The range failure, mainly is base on one or more open burners. The whole amperage of the range will go down, not up. In case of a short circuit, on my experience, most of the time the main breaker will trip before any lower breaker on the house. Like I sad on other post. The 70 amps breaker purpose is to protect the wire, not the appliance. "On a 20 amp branch circuit, you can have as many appliances connected to a branch circuit as you want, as long as you do not overload a receptacle or exceed the 80% limit for the branch circuit."
 
carloslt said:
#6 AWG, THHN wire has an ampacity of 75 amp. It is more than enough for the breaker.
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Only by using the 90 deg column, and it's really unlikely that the terminals are rated for that (try 75 or even 60); that's why we generally use 60 deg column and 55 amps for #6.
If you're being scrupulous, the range may specify a max breaker of 40 or 50 amps, if it says so, that's the max breaker you can put it on.
Leave 20 amp general purpose circuits out of the discussion, they have some separate rules; this is art 422 territory (see 422.11).

Of course, if one isn't concerned about those rules...
 
carloslt said:
#6 AWG, THHN wire has an ampacity of 75 amp. It is more than enough for the breaker.
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It would only have an ampacity of 75 amps if everything its connected to has 90C terminations. Your equipment doesn't. If your breaker is so old you can't find a replacement I highly doubt it even has 75C terminations. It most likely limited to 60C which puts the ampacity of #6 at 55 amps.

If you equipment did have 75C termination you could protect #6 at 70 amps if the load was not more that 65 amps.

As was suggested earlier if you can't get the correct replacement breaker, feed a small enclosure that has the correct size breaker.
 
zbang said:
Only by using the 90 deg column, and it's really unlikely that the terminals are rated for that (try 75 or even 60); that's why we generally use 60 deg column and 55 amps for #6.
If you're being scrupulous, the range may specify a max breaker of 40 or 50 amps, if it says so, that's the max breaker you can put it on.
Leave 20 amp general purpose circuits out of the discussion, they have some separate rules; this is art 422 territory (see 422.11).

Of course, if one isn't concerned about those rules...
Click to expand...

Thanks for taking the time to check the code. It is pretty obvious that I was talking about the 90 deg. Anyway, That does not answer my question. The issue is that the rule of the 50 amp is because the receptacle is a 50 amp. If I remove the receptacle and hardwire the appliance all the way up to the breaker, the 50amp should not apply.
 
carloslt said:
The issue is that the rule of the 50 amp is because the receptacle is a 50 amp. If I remove the receptacle and hardwire the appliance all the way up to the breaker, the 50amp should not apply.
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Huh? The receptacle has nothing to do with it. The breaker ampacity is determined by the #6 wire which is limited to 55A as well as the appliance itself which probably specifies a 50A max breaker.

-Hal
 
carloslt said:
If I remove the receptacle and hardwire the appliance all the way up to the breaker, the 50amp should not apply.
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What then would the limit be? Could you hardwire a range with a 100a circuit?

You still must protect the #6 wire. (Is it cu or al?)
 
NM cable must use 60C ampacity table.

Most everything else that is less than 30-35 years old will be able to use 75C ampacity of 65 amps - next size up rule would allow 70 amp breaker.

I do believe somewhere in art 210 that these sort of cooking appliances are still usually limited to utilization on a 50 amp max branch circuit though.

Maybe an individual appliance on individual circuit is where you can find some exception - probably only if the appliance is rated over 50 amps though and probably not happening with household type ranges either.
 
kwired said:
NM cable must use 60C ampacity table.

Most everything else that is less than 30-35 years old will be able to use 75C ampacity of 65 amps - next size up rule would allow 70 amp breaker.

I do believe somewhere in art 210 that these sort of cooking appliances are still usually limited to utilization on a 50 amp max branch circuit though.

Maybe an individual appliance on individual circuit is where you can find some exception - probably only if the appliance is rated over 50 amps though and probably not happening with household type ranges either.
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422.11(B) would apply to the OP's "Range".
 
If you cant find a 50a breaker can you get a 30 or a 40? Chances are that will be ok.

If 70 is all you can get why not come out with 70A and feed a small fused disco or small panel with modern breakers.

Curious..... what's the breaker/panel type you cant find?
 
mikeames said:
If you cant find a 50a breaker can you get a 30 or a 40? Chances are that will be ok.

If 70 is all you can get why not come out with 70A and feed a small fused disco or small panel with modern breakers.

Curious..... what's the breaker/panel type you cant find?
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We've done this in the past. Old Main Range fuse box. Add sub that could be used in the future as the SE, when the customer can better afford it.
 
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