PC Grounding and Bonding 4

Question 1

What minimum diameter is required for a driven ground rod made of steel or iron per NEC 250.52(A)(5)?

Accepted Answer

5/8 inch

Answer

NEC 250.52(A)(5) requires steel or iron ground rods to be at least 5/8 inch in diameter.

Question 2

In a multi-building installation fed from a single service, which conductor carries fault current back to the source in a subpanel without a neutral-to-ground bond?

Accepted Answer

The equipment grounding conductor (EGC)

Answer

In a subpanel (separately fed structure), the EGC carries fault current back to the main service where the MBJ provides the return path to the source.

Question 3

Under NEC 250.119, which color or marking identifies an equipment grounding conductor for conductors larger than #6 AWG?

Accepted Answer

Green tape, green paint, or other green marking at terminations

Answer

For EGCs larger than #6 AWG, NEC 250.119 allows identification by green tape, green paint, or other green marking at every point where the conductor is accessible.

Question 4

A plate grounding electrode must expose at least how many square feet of surface area to the soil?

Accepted Answer

2 sq ft

Answer

NEC 250.52(A)(7) requires plate electrodes to have at least 2 square feet of surface area in contact with the surrounding soil.

Question 5

Which bonding method is acceptable for rigid metal conduit (RMC) at a service entrance where the conduit is used as the raceway for service-entrance conductors?

Accepted Answer

Listed fittings designed for bonding, grounding bushings, or bonding locknuts

Answer

NEC 250.92(B) permits listed fittings, grounding/bonding bushings, or bonding locknuts for bonding service raceways.

(PC) Professional Electrical Contractor Practice Test

(PC) Professional Electrical Contractor Practice Test

PC Grounding and Bonding 4