NEC Grounding and Bonding 3

Question 1

According to NEC 250.68, how must a grounding electrode conductor connection to a grounding electrode be made?

Accepted Answer

Accessible and using listed means

Answer

NEC 250.68 requires grounding electrode conductor connections to be accessible and made with listed connectors, clamps, or fittings.

Question 2

What is the minimum burial depth for a bare copper grounding electrode conductor run underground per NEC 250.64(B)?

Accepted Answer

No burial depth requirement — it may run exposed if protected

Answer

NEC 250.64(B) allows grounding electrode conductors to be exposed or in a raceway but does not mandate burial; physical protection is required where subject to damage.

Question 3

Per NEC 250.30, what is required at a separately derived system such as a transformer?

Accepted Answer

A system bonding jumper and grounding electrode

Answer

NEC 250.30(A) requires both a system bonding jumper and a grounding electrode for a separately derived system.

Question 4

Which of the following is NOT an acceptable grounding electrode per NEC 250.52?

Accepted Answer

A plastic water pipe

Answer

Plastic water pipe is not conductive and cannot serve as a grounding electrode; NEC 250.52 lists only metal or conductive electrodes.

Question 5

What minimum diameter must a ground rod electrode be if made of stainless steel or listed material per NEC 250.52(A)(5)?

Accepted Answer

5/8 inch

Answer

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

NEC Practice Test

NEC Practice Test

NEC Grounding and Bonding 3