CEP Safety Standards & Compliance 4

Question 1

Which NEC article addresses the requirements for surge-protective devices (SPDs) installed on service entrance equipment?

Accepted Answer

Article 280

Answer

NEC Article 280 covers surge-protective devices (formerly 285 for SPDs), including requirements for those installed at service entrances.

Question 2

In a hazardous location classified as Class I, Division 1, what type of wiring method is required?

Accepted Answer

Threaded rigid metal conduit (RMC) or approved explosion-proof equipment

Answer

Class I, Division 1 locations require threaded RMC, steel intermediate metal conduit, or other NEC-approved methods with explosion-proof seals and fittings.

Question 3

According to OSHA 1926.416, what is the minimum safe approach distance for unqualified workers from unguarded, energized overhead power lines at 50kV?

Accepted Answer

10 feet

Answer

OSHA 1926.416 requires unqualified workers to maintain at least 10 feet from energized overhead lines up to 50kV; above 50kV the distance increases.

Question 4

What is the primary purpose of a main bonding jumper (MBJ) in an electrical service?

Accepted Answer

To connect the neutral (grounded conductor) to the equipment grounding system at the service point

Answer

The main bonding jumper connects the neutral conductor to the equipment grounding conductor and the grounding electrode system at the service, enabling fault current to return and trip overcurrent devices.

Question 5

Under NEC 110.3(B), what is required after installing any listed electrical equipment?

Accepted Answer

Installation and use must comply with the listing and labeling instructions

Answer

NEC 110.3(B) requires that listed and labeled equipment be installed and used in accordance with any instructions included in the listing or labeling.

(CEP) Certified Electrical Professional Practice Test

(CEP) Certified Electrical Professional Practice Test

CEP Safety Standards & Compliance 4