Grounding and Bonding Flashcards

What is the purpose of the bonding jumper at a service panel?

Answer: To connect the neutral bus to the equipment grounding bus

The main bonding jumper connects the neutral bus to the equipment grounding bus at the service entrance panel, establishing the connection between the grounded conductor and the equipment grounding system.

Why must the neutral and ground be bonded at only one point in a distribution system?

Answer: To prevent objectionable current flow on equipment grounding conductors

If neutral and ground are bonded at multiple points, normal return current can flow through equipment grounding conductors, metal raceways, and building steel, creating shock hazards and fire risks.

What is the purpose of an equipment bonding conductor in a raceway system?

Answer: To provide a low-impedance path for fault current back to the source

The equipment bonding conductor provides a low-impedance fault current path from any point of a ground fault back to the source, enabling the overcurrent device to operate quickly and clear the fault.

According to the CEC, what is the minimum bonding conductor size for a circuit protected by a 60 A breaker?

Answer: No. 10 AWG

CEC Table 16 specifies the minimum bonding conductor size based on the overcurrent device rating. For a 60 A circuit, a No. 10 AWG copper bonding conductor is required.

What is an intersystem bonding termination?

Answer: A device providing connection points for bonding communication system grounds to the power system ground

An intersystem bonding termination provides accessible connection points near the service entrance for bonding communication systems (telephone, cable TV, satellite) to the power system's grounding electrode system.

What material must not be used as a sole grounding electrode?

Answer: Aluminium rod driven into the earth

Aluminium is not permitted as a grounding electrode in contact with earth because it corrodes rapidly in soil, losing its electrical connection to earth over time.