309A Grounding and Bonding

Question 1

What is the primary purpose of grounding an electrical system?

Accepted Answer

To stabilize voltage to earth and provide a path for fault current to operate protective devices

Answer

To reduce electricity consumption

Answer

To increase the speed of motors

Answer

To improve power factor

Question 2

What is the difference between grounding and bonding?

Accepted Answer

Grounding connects to earth; bonding connects metallic parts together to maintain equipotential

Answer

They are the same thing

Answer

Bonding connects to earth; grounding connects metallic parts together

Answer

Grounding is for AC systems; bonding is for DC systems

Question 3

According to the CEC, what is the minimum size of a copper grounding electrode conductor for a 100 A service?

Accepted Answer

No. 6 AWG

Answer

No. 8 AWG

Answer

No. 4 AWG

Answer

No. 2 AWG

Question 4

What is a grounding electrode?

Accepted Answer

A conducting object that establishes a direct connection to earth

Answer

A circuit breaker that trips on ground faults

Answer

A type of bonding bushing

Answer

An insulated conductor in a raceway

Question 5

What is the minimum length for a ground rod used as a grounding electrode according to the CEC?

Accepted Answer

3.0 m (10 ft)

Answer

1.5 m (5 ft)

Answer

2.4 m (8 ft)

Answer

3.6 m (12 ft)

Question 6

What is the maximum permitted ground resistance for a single ground rod according to the CEC?

Accepted Answer

25 Ω

Answer

5 Ω

Answer

10 Ω

Answer

15 Ω