CME Grounding, Bonding & Overcurrent Protection

Question 1

What is the minimum size copper equipment grounding conductor (EGC) required for a circuit protected by a 100A overcurrent device per NEC Table 250.122?

Accepted Answer

8 AWG

Answer

NEC Table 250.122 specifies a minimum 8 AWG copper EGC for circuits protected by overcurrent devices rated up to 100A.

Question 2

Per NEC Article 250, what is the primary purpose of bonding metal parts in an electrical system?

Accepted Answer

To establish electrical continuity and conductivity between metal parts

Answer

Bonding establishes electrical continuity and conductivity between conductive parts to ensure a reliable fault current path and equalize potential differences.

Question 3

Which of the following is explicitly prohibited as a grounding electrode per NEC 250.52(B)?

Accepted Answer

Metal underground gas piping system

Answer

NEC 250.52(B) explicitly prohibits metal underground gas piping systems from being used as grounding electrodes due to safety hazards.

Question 4

The main bonding jumper at a service connects which two components?

Accepted Answer

The grounded (neutral) conductor to the equipment grounding conductor at the main service

Answer

Per NEC 250.28, the main bonding jumper connects the grounded (neutral) conductor to the equipment grounding conductor and enclosure at the main service disconnect.

Question 5

Per NEC Table 250.66, what is the minimum size copper grounding electrode conductor (GEC) for a service with 3/0 AWG copper service-entrance conductors?

Accepted Answer

4 AWG

Answer

NEC Table 250.66 requires a 4 AWG copper GEC when the largest service-entrance conductor is 3/0 AWG copper.

(CME) Certified Master Electrician Practice Test

(CME) Certified Master Electrician Practice Test

CME Grounding, Bonding & Overcurrent Protection