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Load Calculation Applications Flashcards

7 cards from real NEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Load Calculation Applications flashcards as text
  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?

    Answer: 65%

    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.

  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?

    Answer: 48 kVA

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

  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?

    Answer: 150 VA per linear foot

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

  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?

    Answer: Electric vehicle supply equipment

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

  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?

    Answer: 5,000 VA

    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.

  6. When using the standard method to calculate a dwelling service, at what square footage threshold does the 3 VA per sq ft lighting load for the first portion end and require a different demand treatment under NEC Table 220.42?

    Answer: The entire load uses demand factors; there is no square footage threshold

    NEC Table 220.42 applies demand factors to the total general lighting load in VA (not square footage), with the first 3,000 VA at 100% and the remainder at 35%.

  7. A three-phase, 208Y/120V panel serves 12 identical 1,500 VA single-phase receptacle loads balanced across phases. What is the total three-phase feeder load before demand factors?

    Answer: 18,000 VA

    Total load = 12 receptacles × 1,500 VA = 18,000 VA, which is then distributed across three phases but the total feeder VA is still 18,000 VA before demand factors.