Grounding and Bonding Flashcards

What is the primary purpose of grounding an electrical system?

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

System grounding stabilizes the voltage relative to earth under normal conditions and provides a low-impedance fault current path that enables overcurrent protective devices to clear ground faults quickly.

What is the difference between grounding and bonding?

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

Grounding establishes a connection to earth, while bonding connects all metallic parts together to ensure they remain at the same potential, preventing shock hazards from voltage differences.

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

Answer: No. 6 AWG

CEC Table 17 specifies a minimum No. 6 AWG copper grounding electrode conductor for services up to 100 A, ensuring adequate capacity to carry fault current to the grounding electrode.

What is a grounding electrode?

Answer: A conducting object that establishes a direct connection to earth

A grounding electrode is a conductive body (such as a ground rod, metal water pipe, or concrete-encased electrode) that makes direct contact with the earth to establish the ground reference.

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

Answer: 3.0 m (10 ft)

CEC Rule 10-700 requires ground rods to have a minimum length of 3.0 m (10 ft) and be driven to their full length to ensure adequate contact with earth for a low-resistance ground connection.

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

Answer: 25 Ω

CEC Rule 10-702 requires a maximum ground resistance of 25 Ω for a single grounding electrode. If this cannot be achieved, additional electrodes must be installed.