CEI Branch Circuit & Feeder Inspection 1 — Questions and Answers
Question 1: Which NEC article specifically covers the installation requirements for branch circuits in dwelling units and commercial buildings?
- Article 200
- Article 210 (Correct answer)
- Article 215
- Article 220
Correct answer: Article 210
NEC Article 210 covers branch circuits, including ratings, required circuits, and outlet placement requirements.
Question 2: What is the maximum load permitted on a 20-ampere branch circuit that supplies continuous loads, per the 80% rule?
- 20 amperes
- 16 amperes (Correct answer)
- 24 amperes
- 18 amperes
Correct answer: 16 amperes
Per NEC 210.19(A)(1), continuous loads must not exceed 80% of the branch circuit rating, so 20A × 80% = 16A maximum.
Question 3: Per NEC 210.11(C)(1), how many small appliance branch circuits are required to serve the kitchen receptacle outlets in a dwelling unit?
- One 20-ampere circuit
- Two 20-ampere circuits (Correct answer)
- Three 15-ampere circuits
- One 30-ampere circuit
Correct answer: Two 20-ampere circuits
NEC 210.11(C)(1) requires at least two 20-ampere small appliance branch circuits to serve kitchen, dining room, and similar areas.
Question 4: What is the minimum conductor size (AWG copper) permitted for a 20-ampere branch circuit?
- 14 AWG
- 12 AWG (Correct answer)
- 10 AWG
- 8 AWG
Correct answer: 12 AWG
Per NEC 210.19(A) and Table 310.16, 12 AWG copper is the minimum conductor size rated for use on 20-ampere branch circuits.
Question 5: Per NEC Article 100, an individual branch circuit is defined as one that:
- Serves two or more outlets simultaneously
- Supplies only one piece of utilization equipment (Correct answer)
- Has no overcurrent protection device
- Uses a multi-wire configuration
Correct answer: Supplies only one piece of utilization equipment
An individual branch circuit, as defined in NEC Article 100, is a branch circuit that supplies only one piece of utilization equipment.
Question 6: Combination-type AFCI protection is required by the 2020 NEC for 120-volt, 15- and 20-ampere branch circuits in which locations of a dwelling unit?
- Garages and unfinished basements only
- Kitchens and bathrooms only
- All habitable rooms and specified areas (Correct answer)
- Bedrooms only
Correct answer: All habitable rooms and specified areas
The 2020 NEC 210.12(A) expanded AFCI requirements to cover all 120V, 15- and 20-ampere branch circuit outlets in virtually all areas of dwelling units.
Question 7: What is the maximum overcurrent device rating permitted for a 15-ampere branch circuit per NEC 210.3?
- 15 amperes (Correct answer)
- 20 amperes
- 25 amperes
- 30 amperes
Correct answer: 15 amperes
NEC 210.3 states the rating of a branch circuit is determined by the rating of the overcurrent device, so a 15-ampere branch circuit may not exceed a 15-ampere OCPD.
CEI Branch Circuit & Feeder Inspection 1
Which NEC article specifically covers the installation requirements for branch circuits in dwelling units and commercial buildings?