NEC Load Calculations 2

Question 1

When calculating the load for a residential kitchen small appliance branch circuits, the NEC requires a minimum of how many 20-ampere circuits?

Accepted Answer

Two 20A circuits

Answer

NEC 210.11(C)(1) requires at least two 20-ampere small appliance branch circuits for receptacle outlets in kitchen, pantry, breakfast room, and dining room.

Question 2

For a 240V, single-phase motor rated at 10 HP, what is the full-load current used for conductor sizing per NEC Table 430.250?

Accepted Answer

50A

Answer

NEC Table 430.250 lists 50A as the full-load current for a 10 HP, 240V, single-phase motor.

Question 3

Under NEC Article 220, what demand factor applies to the first 3,000 VA of general lighting load in a dwelling unit?

Accepted Answer

100%

Answer

NEC Table 220.42 applies 100% demand factor to the first 3,000 VA of lighting load in a dwelling.

Question 4

A commercial building has 40 receptacle outlets in an office area. Using the NEC standard load calculation, what load in VA is assigned per receptacle?

Accepted Answer

180 VA

Answer

NEC 220.14(I) assigns 180 VA per receptacle outlet for calculating branch circuit and feeder loads in commercial occupancies.

Question 5

When calculating a feeder load for a dwelling with a 12 kW electric range, what demand value does NEC Table 220.55 allow for a single range?

Accepted Answer

8,000 VA

Answer

NEC Table 220.55 Column C permits 8 kW (8,000 VA) demand for a single household range rated over 8¾ kW through 12 kW.

NEC Practice Test

NEC Practice Test

NEC Load Calculations 2