NEC Load Calculation Applications 2

Question 1

When calculating the demand load for a commercial kitchen with six 5 kW ovens, what demand factor applies to the first 3 ovens per NEC Table 220.56?

Accepted Answer

65%

Answer

NEC Table 220.56 applies a 65% demand factor to the first three commercial cooking appliances when four or more units are served from the same branch circuit or feeder.

Question 2

A 200-ampere, 240-volt single-phase service supplies a dwelling. What is the net computed load in kVA that represents the full-load capacity of this service?

Accepted Answer

48 kVA

Answer

Net computed load = 200 A × 240 V = 48,000 VA = 48 kVA for a single-phase service.

Question 3

Under NEC 220.14(J), what is the unit load per outlet used for calculating branch-circuit loads for show-window lighting in a commercial occupancy?

Accepted Answer

150 VA per linear foot

Answer

NEC 220.14(J) assigns 150 VA per linear foot of show-window space for branch-circuit load calculation purposes.

Question 4

For optional calculation of a dwelling unit per NEC 220.82, which load is NOT included in the total connected load before applying demand factors?

Accepted Answer

Electric vehicle supply equipment

Answer

NEC 220.82 does not include EVSE in the optional calculation; EV loads are handled separately under Article 625 and NEC 220.57.

Question 5

A 240-volt, 30-ampere dryer circuit serves a single household dryer. Per NEC 220.54, what is the minimum load to use when calculating the feeder demand for one dryer?

Accepted Answer

5,000 VA

Answer

NEC 220.54 requires a minimum load of 5,000 VA (or the nameplate rating if higher) for each household dryer when calculating feeder demand.

NEC Practice Test

NEC Practice Test

NEC Load Calculation Applications 2