Free Licensed Electrical Contractor Special Occupancies and Equipment Questions and Answers

Question 1

An electrician is installing an explosion-proof light fixture in a paint spray booth, which is classified as a Class I, Division 1 location. Which of the following wiring methods is permitted for connecting the fixture within this hazardous location?

Accepted Answer

Threaded rigid metal conduit (RMC) with appropriate seals.

Answer

NEC Article 501.10(A)(1) specifies that in Class I, Division 1 locations, the only permitted wiring methods are threaded rigid metal conduit, threaded steel intermediate metal conduit, or Type MI cable with approved terminations. These methods are required to contain any potential explosion.

Question 2

According to NEC Article 680, what is the GFCI protection requirement for a single-phase, 240-volt motor for a permanently installed swimming pool?

Accepted Answer

GFCI protection is required for all outlets supplying pool motors connected to single-phase, 120-volt through 240-volt branch circuits.

Answer

NEC 680.21(C) requires that outlets supplying pool pump motors connected to single-phase, 120-volt through 240-volt branch circuits shall be provided with ground-fault circuit-interrupter protection for personnel. This applies whether the motor is connected by receptacle or by direct connection.

Question 3

In a hospital designated as a critical care (Category 1) space, which of the following loads would be required to be connected to the critical branch of the Essential Electrical System (EES)?

Accepted Answer

Receptacles and fixed equipment in the operating room.

Answer

According to NEC 517.33(A), the Critical Branch of the EES is designated to supply power for tasks and equipment essential for patient care during a power outage. This specifically includes receptacles, fixed equipment, and certain lighting in critical care areas like operating rooms and intensive care units.

Question 4

A contractor is installing four Level 2 Electric Vehicle Supply Equipment (EVSE) units in a commercial garage. Each unit has a maximum continuous rating of 32A at 240V. According to NEC Article 625, what is the calculated load for the feeder supplying these four units?

Accepted Answer

160A

Answer

NEC 625.41 and 625.42 state that EV charging loads shall be considered continuous loads. For both branch circuits and feeders, the load must be calculated at 125% of the maximum load. Therefore, the calculation is: 4 units * (32A * 1.25) = 4 * 40A = 160A.

Question 5

In a commercial major repair garage where service is performed on gasoline-powered vehicles, and assuming standard ventilation is not provided, how is the area from the floor up to a level of 18 inches above the floor classified?

Accepted Answer

The area is a Class I, Division 2 location.

Answer

NEC 511.3(C)(1)(b) states that for a major repair garage without the specified mechanical ventilation, the entire floor area is classified as a Class I, Division 2 location up to a level of 18 inches above the floor. This is because flammable gasoline vapors are heavier than air and can accumulate in this lower area.

Licensed Electrical Contractor Practice Test

Licensed Electrical Contractor Practice Test

Free Licensed Electrical Contractor Special Occupancies and Equipment Questions and Answers