Load Calculation Applications Flashcards

Per NEC 220.12, what is the minimum general illumination load in VA per square foot for a hospital?

Answer: 2 VA/sq ft

NEC Table 220.12 lists hospitals at 2 VA per square foot for the general lighting load calculation.

When calculating feeder load for fixed electric space heating under NEC 220.51, what percentage of the total connected heating load must be used?

Answer: 100%

NEC 220.51 requires that 100% of the total connected fixed electric space heating load be included in feeder calculations with no demand factor reduction.

A 400-ampere, 208Y/120V, three-phase service is installed. What is the calculated kVA capacity of this service?

Answer: 144 kVA

Three-phase kVA = √3 × 208 V × 400 A ÷ 1000 = 1.732 × 208 × 400 ÷ 1000 ≈ 144 kVA.

Under NEC 220.55, how many household cooking units must be on a single feeder before demand factors from Table 220.55 can be applied?

Answer: Two or more

NEC 220.55 allows demand factors from Table 220.55 to be applied when two or more single-phase household ranges are supplied by a three-phase feeder.

What NEC section governs the calculation of feeder loads for marinas and boatyards?

Answer: 553.12

NEC 553.12 provides the specific feeder and service load calculation requirements for floating buildings and marina receptacle loads.

Per NEC 220.43(A), what load in VA per linear foot is assigned to fixed multioutlet assemblies when appliances are likely to be used simultaneously?

Answer: 180 VA per linear foot

NEC 220.43(A) assigns 180 VA per linear foot for fixed multioutlet assemblies in areas where appliances will be used simultaneously.

When calculating the demand load for a dwelling unit with a 12 kW range using NEC Table 220.55, what is the maximum demand allowed for a single range up to 12 kW?

Answer: 8,000 W

Per NEC Table 220.55, Column C, the maximum demand for a single range rated up to 12 kW is 8,000 W (8 kW).