Licensed Electrical Contractor Electrical Codes & Standards 2 — Questions and Answers
Question 1: Under NEC Article 210, what is the minimum number of 20-ampere small-appliance branch circuits required for a kitchen countertop in a dwelling unit?
- One 15-ampere circuit
- Two 20-ampere circuits (Correct answer)
- Three 20-ampere circuits
- One 20-ampere circuit
Correct answer: Two 20-ampere circuits
NEC 210.11(C)(1) requires at least two 20-ampere small-appliance branch circuits for kitchen countertop receptacles.
Question 2: NEC Article 230 governs services. What is the maximum height above grade level for a service entrance conductor attachment point on a building?
- 18 feet
- 25 feet
- 30 feet (Correct answer)
- No maximum specified
Correct answer: 30 feet
NEC 230.24(A) limits service-drop attachment height to 30 feet above grade at the point of attachment.
Question 3: According to NEC 250.66, the size of the grounding electrode conductor for a copper service entrance conductor of 3/0 AWG is:
- 4 AWG copper (Correct answer)
- 6 AWG copper
- 8 AWG copper
- 2 AWG copper
Correct answer: 4 AWG copper
NEC Table 250.66 specifies a 4 AWG copper grounding electrode conductor for a 3/0 AWG copper service conductor.
Question 4: What NEC article specifically covers wiring methods and installation of conduit fill calculations?
- Article 300
- Article 310
- Chapter 9 Tables (Correct answer)
- Article 250
Correct answer: Chapter 9 Tables
Chapter 9 Tables of the NEC provide the fill calculations used for determining conduit and tubing fill percentages.
Question 5: Under NEC 210.52, GFCI protection is required for all receptacles within how many feet of the outside edge of a bathroom sink?
- 3 feet
- 4 feet
- 5 feet
- 6 feet (Correct answer)
Correct answer: 6 feet
NEC 210.52(D) requires GFCI-protected receptacles for all outlets within 6 feet of the outside edge of a bathroom sink.
Question 6: NEC 404.2(C) requires a grounded conductor (neutral) at switch locations. Which exception allows omission of the neutral at a switch box?
- When a metal conduit system provides the equipment ground
- When the switch controls a 240V load only
- When wiring is installed in conduit and a grounded conductor is not needed for switch operation (Correct answer)
- When the switch is a 3-way type
Correct answer: When wiring is installed in conduit and a grounded conductor is not needed for switch operation
NEC 404.2(C) Exception No. 2 allows omission of the neutral where the wiring method itself provides an equipment grounding path and no neutral is needed for the switch.
Question 7: According to NEC 517.13, patient care areas in healthcare facilities require a redundant grounding path. This is accomplished by:
- Using double-insulated wiring throughout
- Installing an insulated equipment grounding conductor in addition to the metal raceway (Correct answer)
- Providing two separate service entrances
- Using GFCI breakers on all circuits
Correct answer: Installing an insulated equipment grounding conductor in addition to the metal raceway
NEC 517.13 requires an insulated copper equipment grounding conductor run with the circuit conductors in addition to any metal raceway for patient care areas.
Licensed Electrical Contractor Electrical Codes & Standards 2
Under NEC Article 210, what is the minimum number of 20-ampere small-appliance branch circuits required for a kitchen countertop in a dwelling unit?