CME Special Occupancies and Equipment Questions and Answers 1

Question 1

In a hospital's essential electrical system (EES), which of the following loads is required to be connected to the critical branch?

Accepted Answer

Task illumination and select receptacles in the intensive care unit (ICU).

Answer

According to NEC 517.34, the critical branch of the essential electrical system is required to supply power for task illumination, fixed equipment, and select receptacles serving critical patient care spaces, such as intensive care units, where interruption of power could be life-threatening. The main HVAC system and selected elevators are typically on the equipment branch of the EES, while lobby receptacles are generally on the normal power system.

Question 2

An electrician is replacing a single-phase, 240-volt pool filter motor at a residential dwelling. According to NEC Article 680, what is the primary requirement for the branch circuit supplying this motor?

Accepted Answer

It must be protected by a ground-fault circuit-interrupter (GFCI).

Answer

NEC 680.21(C) mandates that outlets supplying pool pump motors connected to single-phase, 120-volt through 240-volt branch circuits must be provided with Class A ground-fault circuit-interrupter protection for personnel, whether supplied by a receptacle or by direct connection.

Question 3

In a commercial garage used for repair and service where adequate ventilation is not provided, what is the default classification for the area extending from the floor up to a level of 18 inches?

Accepted Answer

Class I, Division 2.

Answer

Per NEC 511.3(C)(1)(b), in a major repair garage without four or more air changes per hour, the area from the floor up to 18 inches is classified as a Class I, Division 2 location. This is because flammable gasoline vapors are heavier than air and can accumulate near the floor. Any pit or depression below floor level is considered Class I, Division 1.

Question 4

When installing an equipotential plane in a concrete floor area of an agricultural building where livestock are confined, which of the following is a key requirement according to NEC 547.10?

Accepted Answer

The plane must be connected to the electrical grounding system with a copper conductor, not smaller than 8 AWG.

Answer

NEC 547.10(C) requires the equipotential plane to be bonded to the building's electrical grounding system. The bonding conductor must be copper (insulated, covered, or bare) and not smaller than 8 AWG. This practice helps to reduce voltage gradients (stray voltage) across the concrete surface, which can be harmful to livestock.

Question 5

Which of the following best describes the overcurrent protection requirement for a feeder supplying an electric fire pump motor, according to NEC Article 695?

Accepted Answer

The overcurrent device must be selected or set to carry the motor's locked-rotor current indefinitely.

Answer

According to NEC 695.4(B)(2), the overcurrent protective device for a fire pump must be rated to carry the sum of the locked-rotor currents of the fire pump motor(s) and the full-load current of any associated accessory equipment indefinitely. The primary objective is to ensure the fire pump operates without interruption during a fire, prioritizing its function over protecting the motor from overload.

(CME) Certified Master Electrician Practice Test

(CME) Certified Master Electrician Practice Test

CME Special Occupancies and Equipment Questions and Answers 1