Licensed Electrical Contractor Electrical System Design & Installation 5

Question 1

What is the minimum headroom required in front of electrical equipment rated over 600V in an electrical room, per NEC 110.34?

Accepted Answer

6.5 feet

Answer

NEC 110.34(A) requires a minimum headroom of 6.5 feet in front of electrical equipment rated over 600V in electrical rooms.

Question 2

When designing a service entrance for a large commercial building, which factor primarily determines whether a single or multiple service drops are permitted?

Accepted Answer

Occupancy type and special conditions defined in NEC 230.2

Answer

NEC 230.2 limits buildings to one service, but lists specific exceptions including capacity, fire protection, and different occupancies that permit multiple services.

Question 3

For a dwelling unit kitchen, how many small appliance branch circuits are required by the NEC?

Accepted Answer

At least two 20A circuits

Answer

NEC 210.11(C)(1) requires at least two 20A small appliance branch circuits for kitchen receptacles in dwelling units.

Question 4

Which raceway system is specifically designed for use in corrosive environments such as chemical plants or wastewater treatment facilities?

Accepted Answer

Schedule 80 PVC conduit

Answer

Schedule 80 PVC conduit provides excellent resistance to corrosion from chemicals, moisture, and acids, making it ideal for corrosive industrial environments.

Question 5

A voltage drop of more than 5% from service entrance to the farthest outlet on a branch circuit is generally considered:

Accepted Answer

Excessive per NEC informational notes recommending 3% max for branch circuits

Answer

NEC 210.19(A) informational notes recommend no more than 3% voltage drop on branch circuits and 5% total from service entrance to utilization point.

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Electrical System Design & Installation 5