Electricians: Range wiring and breaker sizing code

[LD1]

And I'll ask, what happens if my 18 or 20 gauge lamp cord tries to pull 19 amps and don't pop the 20a breaker?

 

[newbury]

And I'll ask, what happens if my 18 or 20 gauge lamp cord tries to pull 19 amps and don't pop the 20a breaker?

Since 18 gauge is rated for 7 amps I would think it's the fault of the person that put the wire on the lamp. And the wire will probably get HOT.

/edit - I've a lot of examples of that type of wiring in the place I bought. And they are a pain to trace down.

 

[Inspector507]

And I'll ask, what happens if my 18 or 20 gauge lamp cord tries to pull 19 amps and don't pop the 20a breaker?

If your lamp tries to pull 19A, you've got a problem with the lamp and the cord will probably melt.

 

[jejeosborne]

Glad to see the inspector catching a real problem. I doubt the range cord is rated for 60 amps and as mentioned the outlet isn't. Many people will also wire their homes with 12 gauge wire and install 15 amp receptacles. Don't mind this much as a failed receptacle will likely remain within a box.

 

[k0ua]

And I'll ask, what happens if my 18 or 20 gauge lamp cord tries to pull 19 amps and don't pop the 20a breaker?

If something at the end of the lamp cord drew 19 amps, the cord would get very hot, and melt its insulation, and then the cords wires would likely touch, and draw a lot of current for a very short period of time and the breaker will open. I think what you are getting at of course is that nearby flammable materiel's could be ignited.

 

[LD1]

Yes, that's what I am getting at. If its okay in the case of about all other things that plug in, why not for the range.

But I don't think anyone has directly answered the question though. That is...just because the range says 40a, does that mean it can only be 40? Is there somewhere in the code that stipulates that?

I agree and understand that 40a breaker would be best. But what is best and what is allowable by code are often different. So I am asking what is allowable.

 

[newbury]

Glad to see the inspector catching a real problem. I doubt the range cord is rated for 60 amps and as mentioned the outlet isn't. Many people will also wire their homes with 12 gauge wire and install 15 amp receptacles. Don't mind this much as a failed receptacle will likely remain within a box.

There is no problem using a HEAVIER wire, as long as there is a 15 amp breaker protecting the 15 amp receptacle. I had a kitchen wired last year and we ran some 12 gauge to 15 amp receptacles on 15 amp breakers because we got a great deal on the wire.

 

[jejeosborne]

And I'll ask, what happens if my 18 or 20 gauge lamp cord tries to pull 19 amps and don't pop the 20a breaker?

Yes, that's what I am getting at. If its okay in the case of about all other things that plug in, why not for the range.

But I don't think anyone has directly answered the question though. That is...just because the range says 40a, does that mean it can only be 40? Is there somewhere in the code that stipulates that?

I agree and understand that 40a breaker would be best. But what is best and what is allowable by code are often different. So I am asking what is allowable.

Lamp cords and range cords being overloaded are equally bad. Neither should be allowed to happen. Thus the reason every lamp has wattage limits posted in the bulb base. Same thing with extension cords, they have amp limits posted on the packaging. Can't prevent some fool from overloading an extension cord and typically they are used briefly under a supervised condition. Extension cords are only to be used temporarily thus the codes for outlet spacing maximums in new homes. The range cord is a permanent installation and must be protected by the breaker. Possible grease buildup around ranges and lint buildup around dryers plus unprotected cords.....need I say more? Ok I will, also mice and rodent activity happens in what rooms of most homes?

 

[Inspector507]

LD1 no you will not find it in the NEC that says a range must be 40A or 50A. What you will find is that the range receptacle can not be protected by more than a 50A breaker or fuse. I'll repeat that that is in 210.24.
The NEC does not specifically deal with plug in appliances. But they are to be used according to any listing or labeling which includes manufacturers instructions. That you'll find in 110.3b.
The inspector did not write up that the range was being used improperly. He wrote up that the range circuit was not protected at proper ampacity.
And to answer another question you had, no I did not do that inspection. I don't do home inspections for real estate purposes.

 

[LD1]

Okay, I'll buy that. I am not in compliance with the NEC via not being in compliance with the MFG directions.

But since the house was built in 1995, and I am either the second or third owner, I doubt this range is original.

Not that it matters at this point, again, this is just information seeking as I am going to change the breaker, but......

As an electrician, when wiring a residential house, how do you know what size range they will be using? or that it wont be different in the future? Same goes for dryer and waterheater? Allthough I think 30A feeding them is pretty standard.

I know that this isnt the only time I have seen 60A breakers for a range. Probably 50% of the houses I looked at are 60A ranges, the rest are 50A

 

[jejeosborne]

There is no problem using a HEAVIER wire, as long as there is a 15 amp breaker protecting the 15 amp receptacle. I had a kitchen wired last year and we ran some 12 gauge to 15 amp receptacles on 15 amp breakers because we got a great deal on the wire.

Agree with that. I should have clarified and said 12 gauge wire with appropriate 20 amp breaker using 15 amp outlets.

In your case, if I scored a deal on 12 gauge wire, I would have installed 20 amp breakers (same cost as 15 amp ones) and 20 amp receptacles (minimum increase over 15 amp) and enjoyed the benefits of a stronger circuit. In fact, it is a code requirement to wire kitchens on 20 circuits in my county as well as bathrooms.

 

[OldMasterTech]

Sorry LD1 I could have picked a better time of day to answer your questions. And maybe a better explanation.
With your breakers you are protecting the circuit at it's allowable ampacity. So if you have a 15A circuit, you need all the components to complete that circuit. You need a 15A breaker, wire rated at least 15A and a 15A receptacle. If you need a 50A receptacle, you need a 50A breaker, 50A wire minimum and a 50A receptacle. So you're actually protecting the circuit. You can't plug a 50A range into a 60A circuit because the circuit is not protected properly with with the 60A breaker. You don't have a 60A rated receptacle. Table 210.24 of the 2014 NEC lists the circuit sizes and their protection.
With your cell phone charger, yes you've plugged it into a 15A circuit/receptacle protected by a 15A breaker. The circuit is protected properly.


But now let me say this, I don't have people do things because I "want" them to. I do it according to the code. I hear this every day, "I did it the way you wanted it". It has nothing to do with what I want. If I can't show you in black and white, then you don't have to do it. Actually one of my inspectors no longer has a certification to inspect because he kept tossing his "personal opinion" in at his inspections.

And that is a professional posting, thank you Inspector507!

Folks forget that the NEC, Building Codes and other regs are designed to protect their very lives and inspectors exist to interpret and apply the codes.

 

[JPRambo]

If the original electrician installed the breaker he was wrong. The outlet for the range is the reason the breaker is to be no larger than 50 amp.
If the breaker went bad and the previous owner went to a hardware store and purchased the wrong breaker it still does not make it right. The NEC states the breaker is there to protect the circuit. The circuit at the time of wiring inspection had a 50 amp recectacle. If this was originally a wall mount range/double oven the breaker could be 60 amp because the range could have been rated by the manufacturer at 60 amp.

 

[ericb2400]

I'm not an inspector nor an electrician, but my take on it is that the stove is a dedicated circuit. Ie the only thing plugged into it is the stove. In my house when we moved in 10 years it was new and I was surprised to see just how many dedicated circuits there were. One for the stove, dryer, AC, water heater, refrigerator, MICROWAVE, GARAGE DOOR OPENER.

I guess my point is they are heave amp draw items so that is why the dedicated circuit. General use items are not heavy draw. That is why a 15 or 20 circuit is standard? Most other thing plugged in do not require heave amperage.

Heck sorry I forgot where I was going with that.

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[ericb2400]

Maybe the breaker has to be sized for the lowest amp rated link in the chain. Ie 15 amp outlet 20 amp wire= need for 15 amp breaker.

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[JPRambo]

Maybe the breaker has to be sized for the lowest amp rated link in the chain. Ie 15 amp outlet 20 amp wire= need for 15 amp breaker.

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If only one outlet on a 20 amp breaker it must be a 20 amp outlet. If two or more 15 amp outlets they can be on a 15 amp or a 20 amp breaker.

 

[DarkBlack]

Okay, I'll buy that. I am not in compliance with the NEC via not being in compliance with the MFG directions.

But since the house was built in 1995, and I am either the second or third owner, I doubt this range is original.

Not that it matters at this point, again, this is just information seeking as I am going to change the breaker, but......

As an electrician, when wiring a residential house, how do you know what size range they will be using? or that it wont be different in the future? Same goes for dryer and waterheater? Allthough I think 30A feeding them is pretty standard.

I know that this isnt the only time I have seen 60A breakers for a range. Probably 50% of the houses I looked at are 60A ranges, the rest are 50A

I totally get your analogy regarding a tiny fragile device being allowed to plug into a 15, or 20 amp receptacle. For sure, the breaker can not be relied upon to prevent the appliance from melting or burning.

In your stove case, what they are saying, is that the house's stove receptacle is not rated for the 60 amps that the wiring and breaker are. In other words the breaker, wiring and recepticle have to all be rated.

 

[ultrarunner]

Maybe the original range was a 60 amp hardwired.

Then somewhere along the line the range was replaced with a 50 amp model with a 50 amp cord needing a 50 amp receptacle and the circuit breaker was left unchanged.

 

[B7510HSD]

Maybe the original range was a 60 amp hardwired.

Then somewhere along the line the range was replaced with a 50 amp model with a 50 amp cord needing a 50 amp receptacle and the circuit breaker was left unchanged.

Very well could have been but now there is a 50amp receptacle in the picture which is why it can't have a 60amp breaker!

 

[ultrarunner]

Run into these things all the time...

Sometimes it was just wrong from day one and not caught... more often than not, it was altered at sometime creating the problem.

One of the homes I was selling had a lifetime Hoyt all copper water heater circa 1955 as was the house... the inspector did a lengthy write up on TPR valve and seismic bracing and typically he would be 100% correct to call this out as a code violation 40 years later because just how many homes still have the original 40 year old heater?

Some of the old Berkeley California homes dating from the 20's still have the Humphrey continuous hot water heaters... basically a copper coil with a flame and no storage tank... none of these have TPR valves.

A common electrical defect is not grounded 3 prong outlets when no ground exists... so long a only 2-prong outlets are used... no problem... again, the issue is improper alteration.

Another is lack of safety glass in shower doors, tub enclosures, doors and windows within so many inches of the floor.

It's totally up to you how you respond... ranges are one of those areas where the appliance was traditionally hardwired to a dedicated circuit... even in homes through the 1960's... it was also cheaper to hard wire.

A lamp is not considered stationary... a major appliance is.

My last Home Inspector checked the AC circuit carefully... the cable and breaker is rated at 50 amps and goes to a 30 amp fused disconnect within 4' of the compressor which is fine... the builder had sized the circuit for a larger unit...