CPI Electrical Systems & Wiring Installation 2

Question 1

What is the maximum number of current-carrying conductors permitted in a conduit before derating is required per NEC?

Accepted Answer

3

Answer

NEC requires derating when more than 3 current-carrying conductors are bundled or in a conduit.

Question 2

Which wire gauge is the minimum required for a 20-amp branch circuit in a residential installation?

Accepted Answer

12 AWG

Answer

12 AWG copper wire is the minimum size rated to safely carry 20 amps continuously.

Question 3

A GFCI outlet is required within how many feet of a kitchen sink per NEC requirements?

Accepted Answer

6 feet

Answer

NEC requires GFCI protection for receptacles within 6 feet of a kitchen sink.

Question 4

What color is the grounding conductor in standard US residential wiring?

Accepted Answer

Green or bare

Answer

Equipment grounding conductors must be green, green with yellow stripe, or bare copper per NEC.

Question 5

When installing EMT conduit, what is the maximum distance allowed between supports in a vertical run?

Accepted Answer

10 feet

Answer

NEC 358.30 allows EMT to be supported at intervals not exceeding 10 feet for vertical runs.

(CPI) Certified Professional Installer Practice Test