# Range calculation: N.E.C 220.55??



## Chas3x (Aug 1, 2012)

I'm studying to get my license and need help with one of my test questions/answers
.
One cooktop and two ovens are connected to one branch circuit in a kitchen of a one family dwelling. The cooktop has a nameplate rating of 4kw at 240v, while each oven has a nameplate rating of 5.5kw at 240v. The minimum load calculation for this branch circuit is ______ watts.







I don't understand how they made this equation.
I appreciate the help.
Chas3x


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## A Little Short (Nov 11, 2010)

Chas3x said:


> I'm studying to get my license and need help with one of my test questions/answers
> .
> One cooktop and two ovens are connected to one branch circuit in a kitchen of a one family dwelling. The cooktop has a nameplate rating of 4kw at 240v, while each oven has a nameplate rating of 5.5kw at 240v. The minimum load calculation for this branch circuit is ______ watts.
> View attachment 16469
> ...



Look at note 4 of Table 220.55. That is for branch circuit load.

Edit: I just saw the answer sheet said to reference note 4. Do you understand how to use the table, and how to apply note 4?


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## Magnettica (Jan 23, 2007)

Haven't done one of these in awhile... 

3 appliances become (1) appliance. 

Column C (1) appliance is 8,000 watts. 

4kw + 5.5kw + 5.5 kw is 15kw. 

15kw-8kw = 7kw

Add 5% for each additional kw over 8kw. 

8kw x 35% = 10,800 watts

10.8 kw/ 240 = 45 amps. 

That's off the top of my ahead I could be wrong.


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## Shockdoc (Mar 4, 2010)

When is it legal to run a full size range on #10s ? My last full time gig pulling wires at a Marriot residence inn had me doing that.


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## A Little Short (Nov 11, 2010)

Magnettica said:


> Haven't done one of these in awhile...
> 
> 3 appliances become (1) appliance.
> 
> ...


Wrong!
15kw-12kw= 3k
5% for each kw over 12kw
5% x 3kw=15%
8kw x 15%=1.2kw or 1200 w
8kw + 1.2kw = 9.2kw
or as the test wanted =9200W


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## Chas3x (Aug 1, 2012)

So you reduce the 15kw by the highest kw (12) in column C?


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## Chas3x (Aug 1, 2012)

I just figured it out! I appreciate your help.


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## Magnettica (Jan 23, 2007)

Little-Lectric said:


> Wrong!
> 15kw-12kw= 3k
> 5% for each kw over 12kw
> 5% x 3kw=15%
> ...


It's been awhile. I knew this like the back of my hand for the exam, but now not so much. I would have to check my Tom Henry books if I ever ran into this in the real world. 

Thank you for correcting me. :thumbsup:


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## Magnettica (Jan 23, 2007)

I don't like to make excuses for anything, but it was late and I had woken up from sleeping. I see now where I went wrong.



> 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.*


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## A Little Short (Nov 11, 2010)

Magnettica said:


> It's been awhile. I knew this like the back of my hand for the exam, but now not so much. I would have to check my Tom Henry books if I ever ran into this in the real world.
> 
> Thank you for correcting me. :thumbsup:


No problem, it was fun! I'm usually the one getting corrected!:jester:


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## mrxman (Sep 6, 2012)

Little-Lectric said:


> Wrong!
> 15kw-12kw= 3k
> 5% for each kw over 12kw
> 5% x 3kw=15%
> ...


Thanks for the info.


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## irocin350 (Mar 2, 2011)

Little-Lectric;801021
15kw-12kw= 3k
5% for each kw over 12kw
5% x 3kw=15%
8kw x 15%=1.2kw or 1200 w
8kw + 1.2kw = 9.2kw
or as the test wanted =9200W[/quote said:


> haha thats the way i learned it !!!!


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