Journeyman Electrician’s Exam Journeyman Electrician's Branch Circuits 3 — Questions and Answers
Question 1: When sizing a branch circuit conductor for a continuous load, the conductor must be sized for at least:
- 100% of the load
- 125% of the continuous load plus 100% of non-continuous load (Correct answer)
- 80% of the load
- 115% of the load
Correct answer: 125% of the continuous load plus 100% of non-continuous load
NEC 210.19(A)(1) requires conductors to be sized for 125% of the continuous load plus 100% of non-continuous load.
Question 2: Which of the following loads qualifies as a 'continuous load' per the NEC?
- A load energized for 1 hour
- A load energized for 2 hours
- A load energized for 3 or more hours (Correct answer)
- A load energized for 30 minutes
Correct answer: A load energized for 3 or more hours
NEC Article 100 defines a continuous load as one expected to continue for three or more hours.
Question 3: A branch circuit that supplies two or more outlets or receptacles is classified as:
- An individual branch circuit
- A general-purpose branch circuit (Correct answer)
- A dedicated branch circuit
- A feeder circuit
Correct answer: A general-purpose branch circuit
NEC Article 100 defines a general-purpose branch circuit as one that supplies two or more receptacles or outlets for lighting and appliances.
Question 4: A 240-volt branch circuit to a central air conditioner rated 28 amperes must be protected by an overcurrent device rated no more than:
- 30 amperes (Correct answer)
- 40 amperes
- 50 amperes
- 60 amperes
Correct answer: 30 amperes
For motor-compressor loads, the branch circuit overcurrent protection must not exceed the rating specified on the equipment nameplate, typically the next standard size above 28A is 30A.
Question 5: What is the maximum voltage between conductors permitted for branch circuits supplying receptacles in dwelling units?
- 120 volts
- 150 volts (Correct answer)
- 240 volts
- 277 volts
Correct answer: 150 volts
NEC 210.6(A) limits branch circuit voltage to 150 volts to ground for dwelling unit receptacles used for general lighting and appliances.
Question 6: The laundry branch circuit in a dwelling unit must be rated at least:
- 15 amperes
- 20 amperes (Correct answer)
- 30 amperes
- 40 amperes
Correct answer: 20 amperes
NEC 210.11(C)(2) requires at least one 20-ampere branch circuit for laundry receptacle outlets in a dwelling unit.
Question 7: When a multiwire branch circuit feeds a device that could simultaneously interrupt both hot conductors, the NEC requires:
- A single-pole breaker for each conductor
- A handle-tied or two-pole breaker (Correct answer)
- A GFCI breaker on one conductor only
- No special requirement
Correct answer: A handle-tied or two-pole breaker
NEC 210.4(B) requires multiwire branch circuits to have a means to simultaneously open all ungrounded conductors, such as a handle-tied or two-pole breaker.
Journeyman Electrician’s Exam Journeyman Electrician's Branch Circuits 3
When sizing a branch circuit conductor for a continuous load, the conductor must be sized for at least: