Range cord labelled 40A fed by 50A breaker...

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Electroplaxes

Member
Location
Nunica, MI
I'm on an apartment complex where they are installing multiple ranges. One for each unit, fed by a panel dedicated to each specific unit. They call for 50A breaker, (3)#6awg (1)#10awg to fed a 50A receptacle (14-50r). Over sized I know, its what they wanted, not a big deal.

When the ranges and the cords show up. I grab a whip to double check the receptacles where compatible. This is where it gets fuzzy for me. The bag says UL listed 40A 125/250V range power cord. The plug it?s self is stamped with 40A 125/250V with the cord containing (2)#8awg (2)#10awg.

I'm getting more of a cold shoulder from the equipment guys "hasn't been an issue before". I wanted to make sure before I go to the owner I'm not missing something. I'm trying to help the owner out, I would prefer not to come back looking like an idiot because there is some exception or loop hole.
 

GoldDigger

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Placerville, CA, USA
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I'm on an apartment complex where they are installing multiple ranges. One for each unit, fed by a panel dedicated to each specific unit. They call for 50A breaker, (3)#6awg (1)#10awg to fed a 50A receptacle (14-50r). Over sized I know, its what they wanted, not a big deal.

When the ranges and the cords show up. I grab a whip to double check the receptacles where compatible. This is where it gets fuzzy for me. The bag says UL listed 40A 125/250V range power cord. The plug it?s self is stamped with 40A 125/250V with the cord containing (2)#8awg (2)#10awg.

I'm getting more of a cold shoulder from the equipment guys "hasn't been an issue before". I wanted to make sure before I go to the owner I'm not missing something. I'm trying to help the owner out, I would prefer not to come back looking like an idiot because there is some exception or loop hole.
Do the installation instructions on the range units specify a maximum overcurrent protection device? If they specify 40Amps, then it is for sure an issue.
If the plug self-labelled 40 Amp fits into the 14-50R receptacle, then that by itself is not a problem, but the circuit protection certainly may be.
 

jim dungar

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Staff member
Location
Wisconsin
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PE (Retired) - Power Systems
There are different rules for appliances than there are for general wiring (the more defined the use, the less margin of error is needed)

There are different rules for Listed equipment, then there are for non-listed equipment (the code effectively gives a pass to specific tested equipment).

Have you ever plugged a 1000W space heater into a 15A circuit?
 

kbsparky

Senior Member
Location
Delmarva, USA
LAMP cords are rated for maybe 5-10 Amps. They are routinely plugged into receptacles fed with 15 and 20 Amp circuits.

No problem here? What's the difference in your situation?
 

Electroplaxes

Member
Location
Nunica, MI
The heater and the lamp that you are referring to, are one full piece of equipment manufactured as one unit. The UL listing is of the entire thing (housing, switch, socket, cord, etc). Also both you are plugging these into multi-outlet branch circuits. If you were to dedicate an individual branch circuit for any certain piece of equipment, you then need to consider the equipment when sizing the feed (fixed mounted heater vs. cord plug heater). The ranges and cords I’m dealing with are two separate objects being put together in the field. This could cause an issue in one of two ways.

1)The stove is rated to be protected at 50A and draws what it’s allowed. But according to Table 400.5(A) the cord installed can only handle 35A (SRDT #8awg >2CCC). You base the protection on the weakest link, is the cord not still considered conductors ( 210.19(A)(3) ).

2)The stove is max protected at 40A and now you endanger the stove 422.11(A).
 
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kwired

Electron manager
Location
NE Nebraska
I see welders all the time with factory installed cord and plugs - 50 amp plug 12 or 10 AWG cord. Although they are listed as is- with the cord already installed where the range generally must have the cord field installed.

I don't have much issue with it myself.

What if the building is inspected and finalized before appliances are installed? Who will ever know if the cords installed were 40 or 50 amp. Who will care? How will we ever know if appliance installer even removed the bonding jumpers in the appliances?

What happens a few months or years down the road when a range gets replaced for some reason - who ensures the right thing is done with the replacement.

The premises wiring generally is considered to stop at the receptacle for such a circuit. The range itself, including the cord is not premises wiring.
 

Electroplaxes

Member
Location
Nunica, MI
So it's not a code violation because you cant see it from your house???

I understand that there is not any immediate danger, chances of this ever failing is infinitely rare at best. But why stamp a rating on it if it's to be ignored???

Is it going to affect the job no, is it going to be problem to the company I work for no, it has nothing to do with our contract. Why do I care??? I don't in all honesty, other then I'm curious if someone is intentionally trying to save a buck by install a undersized the whip or are they ignorant to the fact it's to small.
 

jim dungar

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Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
But why stamp a rating on it if it's to be ignored???

What is the rating of the appliance? What size whip does the appliance's instructions call for?

As was hinted at above, we rarely size appliance/device whips based on the branch circuit rating.
 

Electroplaxes

Member
Location
Nunica, MI
What is the rating of the appliance? What size whip does the appliance's instructions call for?

As was hinted at above, we rarely size appliance/device whips based on the branch circuit rating.

Right... it's usually the other way around, figure out what equipment your using, then feed it accordingly. You need to know what your range demands are for your service cal right???
 

Electroplaxes

Member
Location
Nunica, MI
Supposedlly has internal limits at these values....
120/240V - 11.7 kW (48.75A)
120/208V - 8.8 kW (42.3A)

What the heating elements potentially draw...
6" top unit - 1500W
8" top unit - 2600W
Bake unit - 2585W
Broil unit - 3410W
 

kwired

Electron manager
Location
NE Nebraska
What is the rating of the appliance? What size whip does the appliance's instructions call for?

As was hinted at above, we rarely size appliance/device whips based on the branch circuit rating.

Right... it's usually the other way around, figure out what equipment your using, then feed it accordingly. You need to know what your range demands are for your service cal right???

OK, I'll buy that then, but then this becomes a 110.3(B) issue more so than an issue from art 310.

If I am installing the cords on the appliances I will do it right. If I am not installing appliances or cords, an inspector better not gig my installation if they are wrong, as it is not part of my installation. Same goes for if the project is finalized without these appliances in place. We put a receptacle there because we intend for someone to plug something into it, yet have little or no control over just what they plug into it, that goes for any receptacle not just the range.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Supposedlly has internal limits at these values....
120/240V - 11.7 kW (48.75A)
120/208V - 8.8 kW (42.3A)

What the heating elements potentially draw...
6" top unit - 1500W
8" top unit - 2600W
Bake unit - 2585W
Broil unit - 3410W

What does table 220.55 say using these values?
 

Electroplaxes

Member
Location
Nunica, MI
Finally received via email the manufactures spec, and right on the front it say "Breaker size: 40 Amp" lol!!!!! And you watch after all of this, I'd be willing to bet that nothing will come of my inquiries. Like ya'll said, no one pays much attention to appliances after the fact.

Thanks everyone for all your input.....
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
So if you use a 40 amp OCPD with the 50 amp single receptacle you will be OK. Curious about the cord though, what plug configuration does it have?
 
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