CPI Electrical Systems & Wiring Installation 2 — Questions and Answers
Question 1: What is the maximum number of current-carrying conductors permitted in a conduit before derating is required per NEC?
- 2
- 3 (Correct answer)
- 4
- 6
Correct answer: 3
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?
- 14 AWG
- 12 AWG (Correct answer)
- 10 AWG
- 8 AWG
Correct answer: 12 AWG
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?
- 2 feet
- 4 feet
- 6 feet (Correct answer)
- 8 feet
Correct answer: 6 feet
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?
- White
- Gray
- Green or bare (Correct answer)
- Black
Correct answer: Green or bare
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?
- 4 feet
- 6 feet
- 8 feet
- 10 feet (Correct answer)
Correct answer: 10 feet
NEC 358.30 allows EMT to be supported at intervals not exceeding 10 feet for vertical runs.
Question 6: What does the term 'load side' refer to in an electrical panel installation?
- The utility connection entering the panel
- The conductors and devices fed by the panel (Correct answer)
- The grounding electrode system
- The neutral bus bar
Correct answer: The conductors and devices fed by the panel
The load side refers to the conductors, devices, and equipment that receive power from the panel or breaker.
Question 7: Which type of conduit is NOT approved for use in concrete encasement?
- RMC (Rigid Metal Conduit)
- IMC (Intermediate Metal Conduit)
- ENT (Electrical Nonmetallic Tubing) (Correct answer)
- PVC Schedule 40
Correct answer: ENT (Electrical Nonmetallic Tubing)
ENT (smurf tube) is not listed for direct concrete encasement; it is for use in walls and ceilings only.
CPI Electrical Systems & Wiring Installation 2
What is the maximum number of current-carrying conductors permitted in a conduit before derating is required per NEC?