Licensed Electrical Contractor Services, Feeders, and Branch Circuits 2 — Questions and Answers
Question 1: Per NEC 230.71, the maximum number of disconnects permitted for a single service is:
- 2
- 4
- 6 (Correct answer)
- 8
Correct answer: 6
NEC 230.71(A) permits a maximum of six disconnecting means for a service.
Question 2: A feeder supplying a continuous load must have its overcurrent protection device rated at no less than:
- 100% of the continuous load
- 110% of the continuous load
- 125% of the continuous load (Correct answer)
- 150% of the continuous load
Correct answer: 125% of the continuous load
NEC 215.3 requires feeder OCPD ratings to be at least 125% of the continuous load.
Question 3: What is the minimum clearance required above a residential roof for service-entrance conductors with a slope greater than 4 inches in 12 inches?
- 18 inches (Correct answer)
- 3 feet
- 8 feet
- 10 feet
Correct answer: 18 inches
NEC 230.24(A) Exception allows 18-inch clearance above roofs with a slope of 4:12 or greater.
Question 4: Which NEC article covers the installation of feeders?
- Article 210
- Article 215 (Correct answer)
- Article 220
- Article 230
Correct answer: Article 215
Article 215 covers feeder installation requirements.
Question 5: Per NEC 210.19, the minimum ampacity of branch circuit conductors must be at least what percentage of the continuous load plus the non-continuous load?
- 100% of total load
- 115% of continuous plus 100% non-continuous
- 125% of continuous plus 100% non-continuous (Correct answer)
- 125% of total load
Correct answer: 125% of continuous plus 100% non-continuous
NEC 210.19(A)(1) requires conductors rated at 125% of the continuous load plus 100% of the non-continuous load.
Question 6: Service conductors supplying a one-family dwelling must have an ampacity of at least:
- 60 amperes
- 100 amperes (Correct answer)
- 150 amperes
- 200 amperes
Correct answer: 100 amperes
NEC 230.79(C) requires a minimum 100-ampere service for one-family dwellings.
Question 7: A 20-ampere branch circuit is permitted to serve receptacles with a maximum rating of:
- 15 amperes
- 20 amperes (Correct answer)
- 25 amperes
- 30 amperes
Correct answer: 20 amperes
NEC 210.21(B)(1) permits single receptacles on a 20-ampere circuit to be rated 20 amperes.
Licensed Electrical Contractor Services, Feeders, and Branch Circuits 2
Per NEC 230.71, the maximum number of disconnects permitted for a single service is: