# New convection oven on 10/3 and 30 amp



## ccappaul (Dec 3, 2010)

I neeed your code talk here. Dont want the house to burn down

So we pulled out the wall oven here and the cooktop there. Put the new slide in convection oven over sort of here :shifty:. The range has a 50 amp plug:furious: the box has a 30 amp breaker and I dont know if the 10/3 will hold a 50 amp breaker load.

GE says the range load is 40 amp. The joists are open except for about umm 15 feet and I'll open that up if neccesary to run new wire.

So on your instrruction I'll proceed.

Thanks


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## Speedy Petey (Sep 30, 2003)

ccappaul said:


> So we pulled out the wall oven here and the cooktop there. Put the new slide in convection oven over sort of here :shifty:. The range has a 50 amp plug:furious: the box has a 30 amp breaker and I dont know if the 10/3 will hold a 50 amp breaker load.
> 
> GE says the range load is 40 amp.


OK, try again. 

What size wire is the existing circuit? Is that the 10/3?

Wall oven. Cooktop. Slide in conv oven. Range. ...HUH???
What has the 50A cord and plug? The new appliance?

What is the kW rating of the new appliance? 

If this is a typical household range then NO, 10/3 on a 30A breaker is not good at all. 
You would need at least 8/3 on a 40A breaker.


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## ccappaul (Dec 3, 2010)

Speedy Petey said:


> OK, try again.
> 
> What size wire is the existing circuit? Is that the 10/3?
> 
> ...


 
Huh sorry it all made sense on my side but :laughing: I am looking at it:no: 
The existing circuit is 30 amp breaker with 10/3 The new( stove ? convection oven cooktop thing, that my wife really likes) is listed as 12.4 kw at 120/240v. Ge rates it at 40 amp circuit


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## ccappaul (Dec 3, 2010)

ccappaul said:


> Huh sorry it all made sense on my side but :laughing: I am looking at it:no:
> The existing circuit is 30 amp breaker with 10/3 The new( stove ? convection oven cooktop thing, that my wife really likes) is listed as 12.4 kw at 120/240v. Ge rates it at 40 amp circuit


 But you say at least 8/3 on 40 amp so the answer is no to 10/3 and yes to tear the ceiling out for the remaining 15 feet that is covered and run new wire :clap::shutup: Its all part of progress right? 

Should I drop to a 6/3 and run a 50 amp circuit


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## 480sparky (Feb 1, 2009)

ccappaul said:


> .......... Ge rates it at 40 amp circuit


That's all you need. 40 amp circuit, and wire (#8) to carry it.



ccappaul said:


> .........Should I drop to a 6/3 and run a 50 amp circuit


Not unless the nameplate allows a 50a breaker.


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## Speedy Petey (Sep 30, 2003)

Actually, since it is over 12kW it does need a 50A circuit and 6/3. 

I have NO idea how GE can rate a 12.4kW cooking appliance at a 40A circuit. :blink:

By code a *12kW or less* _household_ cooking appliance can be used on a 40A circuit.


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## 480sparky (Feb 1, 2009)

Speedy Petey said:


> Actually, since it is over 12kW it does need a 50A circuit and 6/3.
> 
> I have NO idea how GE can rate a 12.4kW cooking appliance at a 40A circuit. :blink:
> 
> By code a *12kW or less* _household_ cooking appliance can be used on a 40A circuit.


Isn't that for service calculations, and not branch circuit sizing? :blink:


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## Leo G (May 12, 2005)

isn't 12.4KW just over 56 amps on a 220vac circuit?


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## 480sparky (Feb 1, 2009)

Leo G said:


> isn't 12.4KW just over 56 amps on a 220vac circuit?


Yes, but it's *240* these days, Leo. The 50's are long gone. :w00t:


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## Leo G (May 12, 2005)

I am use to 208 circuits.


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## 480sparky (Feb 1, 2009)

Leo G said:


> I am use to 208 circuits.



How nice. I hope your range is rated for it. :thumbsup:


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## Leo G (May 12, 2005)

Actually, mine is. But my house must be 240, I've always called it 220.


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## Speedy Petey (Sep 30, 2003)

480sparky said:


> Isn't that for service calculations, and not branch circuit sizing? :blink:


_*II. Branch-Circuit Ratings 

210.19 Conductors — Minimum Ampacity and Size.

(A) Branch Circuits Not More Than 600 Volts.

(3) Household Ranges and Cooking Appliances.* Branch-circuit conductors supplying household ranges, wall-mounted 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.
_ 

_*220.14 Other Loads — All Occupancies.*
In all occupancies, the minimum load for each outlet for general-use receptacles and outlets not used for general illumination shall not be less than that calculated in 220.14(A) through (L), the loads shown being based on nominal branch-circuit voltages.
*
(B) Electric Dryers and Household Electric Cooking Appliances.* Load calculations shall be permitted as specified in 220.54 for electric dryers and in 220.55 for electric ranges and other cooking appliances._


Then see Table 220.55 for the demand ratings of ranges. A 12kW range uses a demand rating of 8kW.
From 12.1kW to 27kW we _"shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kW."_


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## 480sparky (Feb 1, 2009)

Speedy Petey;1076863[I said:


> ]....[/I]....From 12.1kW to 27kW we _"shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kW."_


What is the* title* of Section 220?


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## Speedy Petey (Sep 30, 2003)

480sparky said:


> What is the* title* of Section 220?


I used to think the same thing until someone pointed out that that part of 220 is also used to size branch circuits for ranges. 

I'll have to search for the reference.


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## Speedy Petey (Sep 30, 2003)

I know that the Handbook commentary is not actual code, but here is the commentary right under Note#1 (over 12kW) of T220.55 :



> For household electric ranges and other cooking appliances, *the size of the conductors must be determined by the rating of the range*. According to Table 220.55, for one range rated 12 kW or less, the maximum demand load is 8 kW (8 kVA per 220.55), and 8 AWG copper conductors with 60°C insulation would suffice. Note that 210.19(A)(3) does not permit the branch-circuit rating of a circuit supplying household ranges with a nameplate rating of 83/4 kW to be less than 40 amperes.


If this does not apply to sizing branch circuits as well as load calcs why would it reference what I put in bold?


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## 480sparky (Feb 1, 2009)

Speedy Petey said:


> I know that the Handbook commentary is not actual code, but here is the commentary right under Note#1 (over 12kW) of T220.55 :
> 
> If this does not apply to sizing branch circuits as well as load calcs why would it reference what I put in bold?



Your references mention 12 and <8¾ kW.... the OP has 12.4.

I think the reason for this minimum is to prevent an installation just like the OP has.... Putting in, say, a 6kW range, which would only require 10 on a 30 a OCP, then having the problem of installing a larger range later on.


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## Speedy Petey (Sep 30, 2003)

Note 1 of T220.55 reads:



> Notes:
> 1. Over 12 kW through 27 kW ranges all of same rating. For ranges individually rated more than 12 kW but not more than 27 kW, the maximum demand in Column C shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kW.


So a 12.4kW range would have a demand of 8.4kW.


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## 480sparky (Feb 1, 2009)

Speedy Petey said:


> Note 1 of T220.55 reads:
> 
> 
> 
> So a 12.4kW range would have a demand of 8.4kW.


220.55 is under *Part III... Feeder & Service Load Calculations*. :shifty:


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## Tinstaafl (Jan 6, 2008)




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## Speedy Petey (Sep 30, 2003)

480sparky said:


> 220.55 is under *Part III... Feeder & Service Load Calculations*. :shifty:


I know that. Somewhere there is something that says to reference this for branch circuits. 

Anyone have any help. I can't find it. :sad:


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## 480sparky (Feb 1, 2009)

Tinstaafl said:


>



No soda?


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## 480sparky (Feb 1, 2009)

speedy petey said:


> i know that. Somewhere there is something that says to reference this for branch circuits.
> 
> Anyone have any help. I can't find it. :sad:



210.21(b)(4)?


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## Tinstaafl (Jan 6, 2008)

I don't want to chance spraying it on my screen. :laughing::jester:


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## 480sparky (Feb 1, 2009)

Tinstaafl said:


> I don't want to chance spraying it on my screen. :laughing::jester:



Clothes-pin your nose. :w00t:


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## Leo G (May 12, 2005)

Hey!! you stole that popcorn dude from my photo site!!!


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## Tinstaafl (Jan 6, 2008)

No, I stole it from Brian. HE stole it from your site. :laughing:


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## 480sparky (Feb 1, 2009)

And Leo stole it from me!:furious:


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## Leo G (May 12, 2005)

I just went back and looked at Brian's popcorn dude and he did indeed steal it from my site. :w00t:

So if you are stealing from a thief is it still stealing? :laughing:


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## Leo G (May 12, 2005)

480sparky said:


> And Leo stole it from me!:furious:


No I didn't, it comes from another site I frequent not mentionable by name on this site. :whistling


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## Tinstaafl (Jan 6, 2008)

Enough of that, let's get back to the electricgument.


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## 480sparky (Feb 1, 2009)

Tinstaafl said:


> Enough of that, let's get back to the electricgument.



The ball's in Speedy's court.


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## Leo G (May 12, 2005)

I stole it from here, I guess it wasn't the forum I was thinking of....

http://www.smiley-faces.org/smiley-faces/smiley-face-popcorn.gif


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## Leo G (May 12, 2005)

I like that one, I think I'll steal it. Now you have something to biotch about.


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## 480sparky (Feb 1, 2009)

Leo G said:


> I like that one, I think I'll steal it. Now you have something to biotch about.










​


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## Speedy Petey (Sep 30, 2003)

Sorry, I was busy with family for a while. My wife hates when I am on here when we have people over. LOL



480sparky said:


> 210.21(b)(4)?


YES, I do believe that's it.


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## Electricmanscot (Feb 6, 2005)

Tinstaafl said:


> Enough of that, let's get back to the electricgument.


Yeah, this is getting good. arty:


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## 480sparky (Feb 1, 2009)

Speedy Petey said:


> ..........YES, I do believe that's it.


That simply says it's allowed, not required.


Damn... I'm out of root beer. Any got a Barq's?


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## Speedy Petey (Sep 30, 2003)

480sparky said:


> That simply says it's allowed, not required.


Well sure. You don't have to size it that way, but you can. If you want to put an 8kW-12kW range on a 50A circuit that is perfectly fine. But a 40A is fine as well.


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## ccappaul (Dec 3, 2010)

*Uh.Hahahaahhahahahahhahahah*

You guys are great :shutup::shutup::shutup::no:

What uh uh uh uh should I do? 

Doesn't seem to me running 6 with a 50 is gonna hurt anything ? 

Right:blink:?

The Popcorn smileys rule thanks for the Laugh and maybe I should have asked for your interpretation of the code talk because i really didn't get it when you posted the actual code:laughing:

Petey you said I could run a 50 and except for the 6 being a little stiff I think thats gonna be my plan


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