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Discussion Starter · #1 ·
Hi all.

This should be my last question on range branch circuits, seeing as they have be answered by the knowledge trades people on this informative forum.

Here is my question: 4-ranges @ 10Kw; 4-ranges @ 11.5; 3-ranges @14kw and 6-ranges @ 15 kw. What is the combined demand factor.

I do not want the answer i perfer to know how to work the problem out. i think i have a general idea, but, i have never done something like this.

i think i would take 4*10; 4*11.5; 3*14; 6*15 but this might not be right either because i am reaching.

If anyone could show me how to work this problem without giving an answer it would be greatly appreciated.
 

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Been a while since I have done range calculations.
But, if I'm not mistaken, you want to find the average of the ranges.
 

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Discussion Starter · #4 ·
Been a while since I have done range calculations.
But, if I'm not mistaken, you want to find the average of the ranges.

Sounds about right. My teacher really didn't go into great detail when teaching this. So, divide them, but after i divide them do i still use the table in 220.55; furthermore, if i did use the chart would i consider them one and the demand factor 8kw?
 

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Table 220.55 Note 2
Over 8 3⁄4 kW through 27 kW ranges of unequal ratings. For ranges individually rated more than 8 3⁄4 kW and of different ratings, but none exceeding 27 kW, an AVERAGE value of rating shall be calculated by adding together the ratings of all ranges to obtain the total connected load (using 12 kW for any range rated less than 12 kW) and dividing by the total number of ranges. Then the maximum demand in Column C shall be increased 5 percent for each kilowatt or major fraction thereof by which this average value exceeds 12 kW.”
 

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4-ranges @ 10Kw;=48KW (using 12 kW for any range rated less than 12 kW)
4-ranges @ 11.5;= 48KW (using 12 kW for any range rated less than 12 kW)
3-ranges @14kw= 42KW
6-ranges @ 15 kw.=90KW
Grand total 17 Ranges and 228KW
228kw/17=13.41 - 12 = 1.41kw
Then the maximum demand in Column C shall be increased 5 percent for each kilowatt or major fraction thereof by which this average value exceeds 12 kW.”

The demand of column C 32 x 1.05(5%)=33.6kw

HAHA if remember it correctly
 

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4-ranges @ 10Kw;=48KW (using 12 kW for any range rated less than 12 kW)
4-ranges @ 11.5;= 48KW (using 12 kW for any range rated less than 12 kW)
3-ranges @14kw= 42KW
6-ranges @ 15 kw.=90KW
Grand total 17 Ranges and 228KW
228kw/17=13.41 - 12 = 1.41kw
Then the maximum demand in Column C shall be increased 5 percent for each kilowatt or major fraction thereof by which this average value exceeds 12 kW.”

The demand of column C 32 x 1.05(5%)=33.6kw

HAHA if remember it correctly
Well, thats not quite what I came up with, like I stated it's been a while.
What were your totals Appropriate tech?
 

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Discussion Starter · #8 ·
Well, thats not quite what I came up with, like I stated it's been a while.
What were your totals Appropriate tech?
Irocin and Gac, i was in class tonight. We were going over some of the calculation for Kitchen Range Branch Circuits and I am sort of lost. A range, A cook-top, and stove. My teacher told me that i was wrong for using the Name Plate when trying to find the Demand factor, for say, a 8kw cook-top or stove; furthermore am i not suppose to use the name plate? I do not understand why the note wouldn't apply to this. Also, could you all please tell me if there is a difference in a stove and a Wall-mounted stove?
 

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Irocin and Gac, i was in class tonight. We were going over some of the calculation for Kitchen Range Branch Circuits and I am sort of lost. A range, A cook-top, and stove. My teacher told me that i was wrong for using the Name Plate when trying to find the Demand factor, for say, a 8kw cook-top or stove; furthermore am i not suppose to use the name plate? I do not understand why the note wouldn't apply to this. Also, could you all please tell me if there is a difference in a stove and a Wall-mounted stove?
So he is telling you not to use the KW rating for branch circuit sizing?
Hmmm wonder if I have been doing this wrong all these years.

Well, a wall mounted oven will have a smaller KW rating,(unless a double oven), than a free standing range.

Obvious answer ... one sits on floor, one is installed in a cabinet:jester:

So, what are you suppose to use to figure branch circuit size?
 

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Discussion Starter · #11 ·
So he is telling you not to use the KW rating for branch circuit sizing?
Hmmm wonder if I have been doing this wrong all these years.

Well, a wall mounted oven will have a smaller KW rating,(unless a double oven), than a free standing range.

Obvious answer ... one sits on floor, one is installed in a cabinet:jester:

So, what are you suppose to use to figure branch circuit size?

First, correct, he is stelling me that i should not use the KW rating.

Secondly, I am told that i should use Column C @ 8 kw for cooktops and stoves. I was looking in my Design book; Stallcups. The Stallcups have examples and in the examples they have a cook-top and it points to the notes and say that cook-top and wall-mounted oven demand load should be its Nameplate Rating. Weird. But on Monday i will be going to the chair of the program and i will be asking him to help with with some of the problems i am having with this class. I do complex mathematical equations all day long. This should not be giving me problems seeing as its only looking up and reading. But, it is giving me a problem.
 
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