IEC - Independent Electrical Contractors Service and Load Calculations Questions and Answers

Question 1

When calculating the service load for a 2,500 sq. ft. single-family dwelling using the standard method, what is the total VA that must be allocated for the required small-appliance and laundry branch circuits before any demand factors are applied?

Accepted Answer

4,500 VA

Answer

3,000 VA

Answer

1,500 VA

Answer

6,000 VA

Question 2

An electrician is calculating the service for a single-family dwelling using the optional method per NEC Article 220, Part IV. The total calculated general load is 32,000 VA. How is the demand factor applied to this load?

Accepted Answer

The first 10,000 VA at 100%, and the remainder at 40%

Answer

The first 3,000 VA at 100%, and the remainder at 35%

Answer

The entire 32,000 VA is taken at 65%

Answer

The entire 32,000 VA is taken at 100%

Question 3

Which of the following loads in a dwelling unit is subject to a 75% demand factor when four or more are fastened in place and served by the same feeder or service?

Accepted Answer

Fixed appliances like a water heater, dishwasher, garbage disposal, and trash compactor

Answer

Electric clothes dryers

Answer

Electric ranges

Answer

Air-conditioning units

Question 4

You are calculating the receptacle load for a 15,000 sq. ft. office building. The plans show 120 individual 125V receptacles. According to NEC 220.14(I) and Table 220.44, what is the calculated load after applying the appropriate demand factor?

Accepted Answer

15,800 VA

Answer

21,600 VA

Answer

15,000 VA

Answer

10,800 VA

Question 5

For a commercial kitchen with six pieces of equipment, NEC 220.56 states that the feeder or service calculated load shall not be less than the sum of the ________.

Accepted Answer

largest two kitchen equipment loads

Answer

ratings of all equipment

Answer

three smallest equipment loads

Answer

largest equipment load plus 50% of the others

Question 6

What is the minimum calculated load for a show-window lighting circuit that runs along a 40-foot base in a retail store, before accounting for it as a continuous load?

Accepted Answer

8,000 VA

Answer

3,000 VA

Answer

1,200 VA

Answer

6,000 VA