article 220.55 question

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steveng

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a dwelling unit kitchen has the following appliances: one 9 kw cooktop and one wall mounted oven rated 5.3kw. the branch circuit calculated load for these appliances is------.

i know the answer, but i dont know how to calculate it based on art 220.55
can someone shed a little light on this.:confused:
 
steveng said:
a dwelling unit kitchen has the following appliances: one 9 kw cooktop and one wall mounted oven rated 5.3kw. the branch circuit calculated load for these appliances is------.

i know the answer, but i dont know how to calculate it based on art 220.55
can someone shed a little light on this.:confused:
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Steve, you need to look at note 4 to table 220.55.

4. Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The branch-circuit load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range.

This would mean using a circuit rated at 60 amps.14300/240=59amps.
Rick
 
Uuumm, but since you can treat it as one range, you get a big discount. A 14.3 KW range as computed per Column C of the table is 12KW range + 10% (2 KW over 12KW means 2 * 5% = 10% increase over a 12 KW range).

A 12 KW range is allowed to be calculated at 8 KW. Adding 10% to this makes 8800 watts = 36.7 amps.

What is strange is that if you were to feed each item separately, you'd need a circuit rated 9KW for just the cooktop. The oven circuit would have to be rated at 5300W. This doesn't doesn't seem right. I would think you should be able to treat the cooktop as 8KW, but that conflicts with Note 4.

Another "clearly written" piece of code by the NEC code making panels.
 
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