Electrician Services and Distribution

Question 1

What is the minimum ampacity required for a service to a single-family dwelling per the NEC?

Accepted Answer

100 amps

Answer

NEC 230.79(C) requires a minimum 100-ampere service for single-family dwellings.

Question 2

What is the purpose of a main disconnect in a service entrance panel?

Accepted Answer

To provide a means to disconnect all power to the premises

Answer

The main disconnect provides a single means to de-energize all branch circuits and feeders within the building.

Question 3

What is the difference between a service lateral and a service drop?

Accepted Answer

A lateral is underground; a drop is overhead

Answer

A service lateral refers to underground service conductors, while a service drop refers to overhead conductors from the utility.

Question 4

What is the maximum number of disconnecting means permitted at a service entrance per the NEC?

Accepted Answer

6

Answer

NEC 230.71 allows a maximum of six disconnects at a single service entrance location.

Question 5

What type of grounding electrode is considered the most effective?

Accepted Answer

Concrete-encased electrode (Ufer ground)

Answer

The concrete-encased electrode (Ufer ground) is considered highly effective because the moisture in concrete provides excellent soil contact.

Electrician Practice Test