# Wiring a Commercial Oven



## A Little Short (Nov 11, 2010)

I was asked to help wire a commercial kitchen and part of the equipment is two commercial ovens.
The ovens are 3Ø and the name plate says:
57A-54A-59A
#4 AWG for supply conductors rated for 75 deg.C

Would a 60A breaker be enough for this? (each oven from a separate 60A breaker)
Also, since normally #6 AWG would be what is needed for 60A, would this be considered resizing or upsizing the conductors since the name plate calls for #4?
If so, I suppose you would need to also upsize the EGC per 250.122(B)-yes?

Something else to muddy the waters a little. If it's not considered upsizing since the nameplate calls for it, and you use #2, that would be upsizing from the name plate listing. And then you calculate for the #2 upsizing, would you use the name plate listing for the calculation or from what a 60A conductor would normally be, which would be #6?


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## Dennis Alwon (May 9, 2009)

I'll give my answer here also this way I can be wrong twice.. 

Well looking at 422.11(E)(3) states that if the appliance OCPD is not marked then you can go 150% of the units marked current. Basically you could use a 90 amp breaker on the unit. I would probably use a 70 amp breaker which would require a #8 EGC and there would be no issues using a #4 CCC


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## HARRY304E (Sep 15, 2010)

Dennis Alwon said:


> I'll give my answer here also this way I can be wrong twice..


You're never wrong...:laughing:


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## A Little Short (Nov 11, 2010)

Dennis Alwon said:


> I'll give my answer here also this way I can be wrong twice..
> 
> Well looking at 422.11(E)(3) states that if the appliance OCPD is not marked then you can go 150% of the units marked current. Basically you could use a 90 amp breaker on the unit. I would probably use a 70 amp breaker which would require a #8 EGC and there would be no issues using a #4 CCC


I'll reply here too, so I can get more confused!:blink:
Since 411.11(E)(3) says "single non-motor-operated appliance" I don't know if this would apply since there are motors in the ovens. I assume for fans, I didn't open the doors to see if they had any type of rotissorie or conveyor, but I did see a motor, maybe 2 in the back. I also think the nameplate said the motor part used 5A at 208V, which I think is single Ø.

I forgot about the 5A listed for the motor on the name plate in the OP.


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## A Little Short (Nov 11, 2010)

Little-Lectric said:


> I was asked to help wire a commercial kitchen and part of the equipment is two commercial ovens.
> The ovens are 3Ø and the name plate says:
> 57A-54A-59A
> #4 AWG for supply conductors rated for 75 deg.C
> ...





Little-Lectric said:


> I'll reply here too, so I can get more confused!:blink:
> Since 411.11(E)(3) says "single non-motor-operated appliance" I don't know if this would apply since there are motors in the ovens. I assume for fans, I didn't open the doors to see if they had any type of rotissorie or conveyor, but I did see a motor, maybe 2 in the back. I also think the nameplate said the motor part used 5A at 208V, which I think is single Ø.
> 
> I forgot about the 5A listed for the motor on the name plate in the OP.


To add to this, I don't think the ovens would be considered continuous since they have a thermostat. With the thermostat, they wouldn't run for 3 hours at full rated current.

Also, another electrician came up with the 60A, and I think it should be larger, such as an 80A.


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## A Little Short (Nov 11, 2010)

I would like to thank everyone (Dennis) that replied to this thread.:laughing:

Maybe I should have made it a poll!:jester:


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