FREE TN LLE Grounding and Bonding Questions and Answers

Question 1

According to the NEC, what is the primary purpose of bonding an electrical system?

Accepted Answer

To establish a low-impedance path for fault current to facilitate the operation of overcurrent devices.

Answer

To limit voltage imposed by lightning.

Answer

To stabilize voltage to earth during normal operation.

Answer

To connect the electrical system to a grounding electrode.

Question 2

A residential service is supplied by 2/0 AWG copper service-entrance conductors. What is the minimum size copper Grounding Electrode Conductor (GEC) required for a connection to a ground rod?

Accepted Answer

6 AWG

Answer

8 AWG

Answer

4 AWG

Answer

2 AWG

Question 3

In a residential dwelling, an electrician is installing a new subpanel in a detached garage fed from the main service panel at the house. Which of the following is a critical requirement for grounding and bonding at the subpanel?

Accepted Answer

A separate grounding electrode, such as a ground rod, must be installed at the detached garage.

Answer

The neutral bus and the equipment grounding bus must be connected together by a main bonding jumper.

Answer

The equipment grounding conductor must be oversized by 25% to account for voltage drop.

Answer

The grounded (neutral) conductor can be used to ground the subpanel enclosure.

Question 4

When a metal underground water pipe is used as a grounding electrode, the connection of the grounding electrode conductor must be made:

Accepted Answer

Within the first 5 feet of the pipe's point of entrance into the building.

Answer

At any accessible point on the interior piping system.

Answer

Only on the street side of the water meter.

Answer

After the main water shut-off valve.

Question 5

Which of the following BEST describes an 'effective ground-fault current path'?

Accepted Answer

An intentionally constructed, low-impedance conductive path designed to carry current under fault conditions from the point of a ground fault to the electrical supply source.

Answer

A connection to the earth through a grounding electrode with a resistance of 25 ohms or less.

Answer

The structural steel frame of a building that is in direct contact with the earth.

Answer

A path that utilizes the grounded (neutral) conductor to clear a fault.

Question 6

An electrician is running a 60-amp branch circuit to supply an appliance. According to NEC Table 250.122, what is the minimum size copper equipment grounding conductor (EGC) required for this circuit?

Accepted Answer

10 AWG

Answer

12 AWG

Answer

8 AWG

Answer

6 AWG