BRANCH-CIRCUIT, FEEDER, AND SERVICE CALCS 70-57

Table 220-19. Demand Loads for Household Electric Ranges, Wall-Mounted Ovens, Counter-Mounted Cooking Units, and Other Household Cooking Appliances over 13/4 kW Rating. Column A to be used in all cases except as otherwise permitted in Note 3 below Maximum Demand Factors Demand Percent Number of (See Notes) (See Note 3) Appliances Column A Column B Column C (Not over 12 (Less than 3½ (3½ kW to 83/4 kW Rating) kW Rating) kW Rating) 1 8 kW 80% 80% 2 11 kW 75% 65% 3 14 kW 70% 55% 4 17 kW 66% 50% 5 20 kW 62% 45% 6 21 kW 59% 43% 7 22 kW 56% 40% 8 23 kW 53% 36% 9 24 kW 51% 35% 10 25 kW 49% 34% 11 26 kW 47% 32% 12 27 kW 45% 32% 13 28 kW 43% 32% 14 29 kW 41% 32% 15 30 kW 40% 32% 16 31 kW 39% 28% 17 32 kW 38% 28% 18 33 kW 37% 28% 19 34 kW 36% 28% 20 35 kW 35% 28% 21 36 kW 34% 26% 22 37 kW 33% 26% 23 38 kW 32% 26% 24 38 kW 31% 26% 25 40 kW 30% 26% 26-30 15 kW plus 1 kW 30% 24% 31-40 for each range 30% 22% 41-50 25 kW plus 3/4 30% 20% 51-60 kW for each 30% 18% 61 and over range 30% 16% Note 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 A shall be increased 5 percent for each additional kW of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kW. Note 2. Over 83/4 kW through 27 kW ranges of unequal ratings. For ranges individually rated more than 83/4 kW and of different ratings, but none exceeding 27 kW, an average value of rating shall be computed 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; and then the maximum demand in Column A shall be increased 5 percent for each kW or major fraction thereof by which this average value exceeds 12 kW. 70-58 NATIONAL ELECTRICAL CODE Note 3. Over 13/4 kW through 83/4 kW. In lieu of the method provided in Column A, it shall be permissible to add the nameplate ratings of all ranges rated more than 13/4 kW but not more than 83/4 kW and multiply the sum by the demand factors specified in Column B or C for the given number of appliances. Note 4. Branch-Circuit Load. It shall be permissible to compute the branchcircuit load for one range in accordance with Table 220-19. 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 computed by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range. Note 5. This table also applies to household cooking appliances rated over 13/4 kW and used in instructional programs. (FPN No. 1): See Table 220-20 for commercial cooking equipment. (FPN No. 2): See Examples, Chapter 9. Table 220-20. Feeder Demand Factors for Kitchen Equipment- Other than Dwelling Unit(s) Number of Units Demand Factors of Equipment Percent 1 100 2 100 3 90 4 80 5 70 6 and over 65 220-21. Noncoincident Loads. Where it is unlikely that two dissimilar loads will be in use simultaneously, it shall be permissible to omit the smaller of the two in computing the total load of a feeder. 220-22. Feeder Neutral Load. The feeder neutral load shall be the maximum unbalance of the load determined by this article. The maximum unbalanced load shall be the maximum net computed load between the neutral and any one ungrounded conductor, except that the load thus obtained shall be multiplied by 140 percent for 3-wire, 2-phase or 5-wire, 2-phase systems. For a feeder supplying household electric ranges, wall-mounted ovens, countermounted cooking units, and electric dryers, the maximum unbalanced load shall be considered as 70 percent of the load on the ungrounded conductors, as determined in accordance with Table 220-19 for ranges and Table 220-18 for dryers. For 3-wire dc or single-phase ac, 4-wire, 3-phase, 3-wire, 2-phase, or 5-wire, 2-phase systems, a further demand factor of 70 percent shall be permitted for that portion of the unbalanced load in excess of 200 amperes. There shall be no reduction of the neutral capacity for that portion of the load that consists of electric-discharge lighting, electronic computer/data processing, or similar equipment, and supplied from a 4-wire, wye-connected, 3-phase system nor the grounded conductor of a 3-wire circuit consisting of two phase wires and the neutral of a 4-wire, 3-phase wye-connected system.