Licensed Electrical Contractor Load Calculation and Services 2

Question 1

When applying the optional calculation method for a dwelling unit, what is the minimum load in volt-amperes applied to the first 10 kVA of all other loads?

Accepted Answer

100%

Answer

Under NEC 220.82, the first 10 kVA of all other loads is calculated at 100%, with the remainder at 40%.

Question 2

A 240V, single-phase service feeds a 10 kW electric range. Using the standard calculation method, what demand load from NEC Table 220.55 applies for one range?

Accepted Answer

8 kW

Answer

NEC Table 220.55, Column C specifies an 8 kW demand for a single household range rated up to 12 kW.

Question 3

What is the minimum size service required for a single-family dwelling under NEC 230.79?

Accepted Answer

100 amperes

Answer

NEC 230.79(C) requires a minimum 100-ampere, 3-wire service for a single-family dwelling.

Question 4

When calculating feeder neutral load for a residential service, how is the unbalanced load between lines reduced per NEC 220.61?

Accepted Answer

The portion of neutral load above 200A may be reduced by 70%

Answer

NEC 220.61(B)(1) permits the neutral load above 200A to be multiplied by 70% for further reduction.

Question 5

A commercial occupancy has 50,000 VA of receptacle load. What demand factor applies to the receptacle load above 10,000 VA per NEC Table 220.44?

Accepted Answer

50%

Answer

NEC Table 220.44 allows the receptacle load exceeding 10,000 VA to be calculated at 50% demand.

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Load Calculation and Services 2