CPI Electrical Systems & Wiring Installation 3

Question 1

What is the purpose of a bonding jumper in an electrical system?

Accepted Answer

To connect grounding conductors to ensure electrical continuity

Answer

A bonding jumper ensures electrical continuity between metal parts, providing a path for fault current.

Question 2

Under NEC, what is the minimum burial depth for Schedule 80 PVC conduit under a residential driveway?

Accepted Answer

12 inches

Answer

Schedule 80 PVC under a residential driveway requires a minimum burial depth of 12 inches per NEC Table 300.5.

Question 3

An arc fault circuit interrupter (AFCI) breaker is designed primarily to protect against:

Accepted Answer

Electrical arcs that can ignite fires

Answer

AFCI breakers detect dangerous arcing conditions in wiring that can cause electrical fires.

Question 4

What is the correct torque specification practice when terminating conductors at breaker lugs?

Accepted Answer

Follow the manufacturer's listed torque value in inch-pounds

Answer

NEC 110.14(D) requires terminals to be tightened to the torque values listed by the manufacturer.

Question 5

In a 3-way switch circuit, what type of wire is used to connect the two 3-way switches?

Accepted Answer

14/3 NM-B cable

Answer

14/3 NM-B provides the two traveler wires plus neutral needed to wire a 3-way switch circuit.

(CPI) Certified Professional Installer Practice Test