CEA CEA Grounding, Bonding, and Electrical Service Equipment Questions and Answers 3

Question 1

In a residential service panel, the neutral bar and the equipment grounding bar must be bonded together at which location?

Accepted Answer

Only at the main service panel

Answer

The neutral and ground bars are bonded together only at the main service panel; in sub-panels they must be kept separate to prevent parallel neutral current paths.

Question 2

What is the minimum ampere rating for a service entrance conductor supplying a single-family dwelling per NEC 230.79?

Accepted Answer

100 amperes

Answer

NEC 230.79(C) requires a minimum 100-ampere, 3-wire service for any single-family dwelling.

Question 3

Service entrance conductors must be protected from physical damage. What is the maximum length of service entrance cable permitted to run along the outside of a building before entering it, without additional protection per the NEC?

Accepted Answer

The service drop attachment point to the service entrance; no run limit applies if it follows the roofline/wall

Answer

Service entrance conductors on the outside of a building may run along the building surface from the service drop to the service equipment without a specific length limitation, as long as they are attached and protected.

Question 4

What is the purpose of a surge protective device (SPD) installed at the service panel?

Accepted Answer

To limit transient overvoltages from lightning or utility switching from reaching equipment

Answer

An SPD clamps transient voltage surges (from lightning or switching) to safe levels, protecting downstream equipment from damage.

Question 5

When installing service entrance conductors in a raceway, what must be done if the raceway passes through a roof or exterior wall?

Accepted Answer

Seal the raceway opening with an approved fitting or sealant to prevent water entry

Answer

Raceways containing service entrance conductors must be sealed where they enter a building to prevent water, insects, and gases from traveling along the conduit into the structure.

(CEA) Certified Electrical Apprentice Practice Test

(CEA) Certified Electrical Apprentice Practice Test

CEA CEA Grounding, Bonding, and Electrical Service Equipment Questions and Answers 3