Electrician Exam Prep2026 NEC · Journeyman · Master Free practice test

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Dwelling load calculations

A dwelling load problem has two stages and the exam tests whether you keep them apart. First add the connected load: general lighting by floor area, the small-appliance circuits and the laundry circuit. Then, only if the question asks for it, apply the demand factor table to that total.

The method

  1. General lighting: multiply the floor area by the unit load for dwellings.
  2. Small-appliance circuits: 1,500 VA for each one.
  3. Laundry circuit: 1,500 VA.
  4. Add the three. That is the connected load.
  5. Demand factor: the first 3,000 VA count at 100% and the amount above 3,000 VA at 35%.

The 2026 NEC moved the load calculation rules from Article 220 to Article 120, so the section numbers in a 2026 problem differ from older books. The worked problems below cite the 2026 sections.

Read the last line of the question before you start. If it asks for the connected load, the demand factor does not belong in the answer.

Worked problems

Problem 1. A single-family dwelling has 4250 square feet of habitable floor area, 4 small-appliance branch circuits and one laundry circuit. What is the general lighting load after applying the demand factor?

Answer: 7,550 VA

General lighting, 120.41: 4250 x 2 = 8,500 VA. Small appliance, 120.52(A): 4 x 1500 = 6,000 VA. Laundry, 120.52(B): 1500 VA. Total connected = 16,000 VA. Table 120.45: first 3000 VA at 100%, the remainder at 35%. 3000 + (16,000 - 3000) x 0.35 = 7,550 VA.

Reference: NEC 120.41, 120.52(A) and 120.52(B), Table 120.45

Problem 2. A single-family dwelling has 2250 square feet of habitable floor area, 3 small-appliance branch circuits and one laundry circuit. What is the total connected load before any demand factor is applied?

Answer: 10,500 VA

General lighting, 120.41: 2250 x 2 = 4,500 VA. Small appliance, 120.52(A): 3 x 1500 = 4,500 VA. Laundry, 120.52(B): 1500 VA. Total connected = 10,500 VA. The demand factor of Table 120.45 does NOT belong here: the question asks for the connected load, which is what you feed INTO that table.

Reference: NEC 120.41, 120.52(A) and 120.52(B)

Problem 3. A single-family dwelling has 4175 square feet of habitable floor area, 2 small-appliance branch circuits and one laundry circuit. What is the general lighting load after applying the demand factor?

Answer: 6,448 VA

General lighting, 120.41: 4175 x 2 = 8,350 VA. Small appliance, 120.52(A): 2 x 1500 = 3,000 VA. Laundry, 120.52(B): 1500 VA. Total connected = 12,850 VA. Table 120.45: first 3000 VA at 100%, the remainder at 35%. 3000 + (12,850 - 3000) x 0.35 = 6,448 VA.

Reference: NEC 120.41, 120.52(A) and 120.52(B), Table 120.45

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Common questions

What is the demand factor for dwelling general lighting?

The first 3,000 VA are taken at 100% and the remainder at 35%, up to the next step of the table.

How many volt-amperes is a small-appliance circuit?

1,500 VA for each small-appliance branch circuit, and 1,500 VA for the laundry circuit.