2017 NEC Table 220.55

E

ENH

Member
Location
Tennessee
Occupation
Electrician
There is a multifamily dwelling with 32 units and each unit has a 18kw range. According to table 220.55 , (for ranges not over 12kw) you would calculate the load at 15 kw plus 1kw for each additional range. Note 1 says the maximum demand in column C shall be increased 5 percent for each 1kw above 12kw. So 15w X 1.3 equals 19.5. 19.5 plus 31 other ranges at 1kw would equal a 50.5 kw demand.

Do I also need to multiply the 1 kw for each additional range by 1.3 since the ranges are 6kw above the 12kw rating at the top of the column? Note 1 states "the maximum demand shall be increased 5 percent for each kilowatt rating".

Thank you in advance!
 
ENH said:
Do I also need to multiply the 1 kw for each additional range by 1.3 since the ranges are 6kw above the 12kw rating at the top of the column? Note 1 states "the maximum demand shall be increased 5 percent for each kilowatt rating".
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Yes, as per Dennis's computation. The extra 1 kW per range is part of the "maximum demand in Column C".

The fact that they chose to present the table with rows 26-40 as a formula for Column C rather than computing each row for you doesn't change anything. So first you do the computation specified in the Table, then you apply Note 1 to that result.

Cheers, Wayne
 
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