Section E3704 Feeder Requirements
The minimum load in volt-amperes shall be calculated in accordance with the load calculation procedure prescribed in Table E3704.2(1). The associated table demand factors shall be applied to the actual load to determine the minimum load for feeders. (220.40)
(Table 220.12, 220.14, Table 220.42, 220.50, 220.51, 220.52, 220.53, 220.54, 220.55, and 220.60) FEEDER LOAD CALCULATION
|LOAD CALCULATION PROCEDURE||APPLIED DEMAND FACTOR|
Lighting and receptacles: A unit load of not less than 3 VA per square
foot of total floor area shall constitute the lighting and 120-volt, 15-and 20-ampere general use receptacle load. 1,500 VA shall be
|100 percent of first 3,000 VA or less and 35 percent of that in excess |
of 3,000 VA.
|Appliances and motors: The nameplate rating load of all fastened-in-|
place appliances other than dryers, ranges, air-conditioning and space-heating equipment.
|100 percent of load for three or less appliances. |
75 percent of load for four or more appliances.
|Fixed motors: Full-load current of motors plus 25 percent of the full load current of the largest motor.|
|Electric clothes dryer: The dryer load shall be 5,000 VA for each dryer circuit or the nameplate rating load of each dryer, whichever is greater.|
|Cooking appliances: The nameplate rating of ranges, wall-mounted |
ovens, counter-mounted cooking units and other cooking appliancesrated in excess of 1.75 kVA shall be summed.
|Demand factors shall be as allowed by Table E3704.2(2).|
|Plus the largest of either the heating or cooling load|
|Largest of the following two selections: |
For SI: 1 square foot = 0.0929 m2.
TABLE E3704.2(2) (220.55 and Table 220.55)
DEMAND LOADS FOR ELECTRIC RANGES, WALL-MOUNTED OVENS, COUNTER-MOUNTED COOKING UNITS AND OTHER COOKING APPLIANCES OVER 13/4 kVA RATINGa, b
|NUMBER OF APPLIANCES||MAXIMUM DEMANDb, c||DEMAND FACTORS (percent)d|
|Column A |
maximum 12 kVA rating
|Column B |
less than 31/2 kVA rating
|Column C |
31/2 to 83/4 kVA rating
- Column A shall be used in all cases except as provided for in Footnote d.
- For ranges all having the same rating and individually rated more than 12 kVA but not more than 27 kVA, the maximum demand in Column A shall be increased 5 percent for each additional kVA of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kVA.
- For ranges of unequal ratings and individually rated more than 8.75 kVA, but none exceeding 27 kVA, an average value of rating shall be computed by adding together the ratings of all ranges to obtain the total connected load (using 12 kVA for any ranges rated less than 12 kVA) and dividing by the total number of ranges; and then the maximum demand in Column A shall be increased 5 percent for each kVA or major fraction thereof by which this average value exceeds 12 kVA.
- Over 1.75 kVA through 8.75 kVA. As an alternative to the method provided in Column A, the nameplate ratings of all ranges rated more than 1.75 kVA but not more than 8.75 kVA shall be added and the sum shall be multiplied by the demand factor specified in Column B or C for the given number of appliances.