Licensed Electrical Contractor Licensed Electrical Contractor Grounding and Bonding Questions and Answers 3

Question 1

What type of grounding electrode is formed by at least 20 feet of steel reinforcing bars (rebar) tied together within a concrete foundation?

Accepted Answer

Concrete-encased electrode

Answer

Ground ring

Answer

Plate electrode

Answer

Rod electrode

Question 2

Per NEC 250.64(E), when multiple service disconnects are located in separate enclosures, how may the grounding electrode conductor be run?

Accepted Answer

It may be tapped using listed connectors at each enclosure

Answer

Only as a single unspliced conductor to one disconnect

Answer

It must be looped through each enclosure without splice

Answer

A separate full-size conductor is required to each disconnect

Question 3

What is the minimum burial depth required for a driven ground rod to be effective per NEC 250.53(G)?

Accepted Answer

8 feet

Answer

4 feet

Answer

6 feet

Answer

10 feet

Question 4

Which of the following is an acceptable method for bonding around a water meter to maintain grounding continuity?

Accepted Answer

Installing a bonding jumper across the meter

Answer

Wrapping the meter with electrical tape

Answer

Relying on the meter's internal metal components

Answer

Using a plastic fitting on one side of the meter

Question 5

According to NEC 250.122, how is the minimum size of an equipment grounding conductor determined for a branch circuit?

Accepted Answer

By the rating of the overcurrent device protecting the circuit

Answer

By the size of the ungrounded conductors

Answer

By the length of the circuit run

Answer

By the type of raceway used

Question 6

What is the purpose of the main bonding jumper at the service equipment?

Accepted Answer

To connect the neutral bus to the equipment grounding bus

Answer

To provide overcurrent protection for the grounding system

Answer

To isolate the grounded conductor from the enclosure

Answer

To reduce electromagnetic interference in the panel