Commercial Load Calculations Flashcards

Per NEC 220.14(H), what VA per linear foot is used for multioutlet assemblies where simultaneous use is likely in a commercial setting?

Answer: 180 VA per foot

When simultaneous use of multioutlet assemblies is likely, NEC 220.14(H)(2) requires 180 VA per foot of the assembly.

When calculating sign lighting load for a commercial building per NEC 220.14(F), what is the minimum VA for each commercial occupancy?

Answer: 1,200 VA

NEC 220.14(F) requires a minimum of 1,200 VA for sign or outline lighting for each commercial occupancy with ground-floor frontage.

For a commercial building with 30 kW of general lighting load, what demand factor reduction is permitted per NEC Table 220.42?

Answer: 100% of first 12,500 VA plus 50% of remainder

Per NEC Table 220.42, commercial occupancies use 100% of the first 12,500 VA and 50% of the remainder for general lighting demand calculations.

What is the standard method for calculating the neutral load on a 3-phase, 4-wire commercial service?

Answer: Maximum unbalanced load between any phase and neutral

The neutral conductor must be sized for the maximum unbalanced load — the greatest load between any single phase and neutral.

Per NEC 220.44, what demand factor can be applied to receptacle loads exceeding 10 kVA in a commercial building?

Answer: 100% of first 10 kVA plus 50% of remainder

NEC 220.44 permits a demand factor of 100% for the first 10 kVA of receptacle load and 50% for the amount exceeding 10 kVA in non-dwelling occupancies.

A Tennessee LLE is sizing a service for a small commercial office with 4,000 sq ft. Using NEC Table 220.12 at 3.5 VA/sq ft, what is the calculated general lighting load?

Answer: 14,000 VA

4,000 sq ft x 3.5 VA/sq ft = 14,000 VA for the general lighting load before demand factors.