Journeyman Electrician’s Exam Journeyman Electrician's NEC 5 — Questions and Answers
Question 1: NEC 700.12 specifies legally required standby and emergency system power sources. Which of the following is NOT an acceptable power source for an emergency system?
- Storage battery
- Generator set
- Uninterruptible power supply (UPS)
- Utility company's second service feed (Correct answer)
Correct answer: Utility company's second service feed
A second utility feed is not an acceptable emergency power source because both feeds can fail simultaneously during a utility outage or disaster.
Question 2: Under NEC 550.25, manufactured homes must have a minimum service entrance rating. What is the minimum ampere rating required for a manufactured home service?
- 60 amperes
- 100 amperes (Correct answer)
- 150 amperes
- 200 amperes
Correct answer: 100 amperes
NEC 550.25 requires manufactured homes to have a minimum 100-ampere service for a 3-wire, 120/240-volt supply.
Question 3: According to NEC 404.8(A), switches and circuit breakers used as switches must be located so they can be operated from a readily accessible location. What is the maximum height for the center of the grip of a switch handle?
- 5 feet 6 inches (66 in)
- 6 feet (72 in)
- 6 feet 7 inches (79 in) (Correct answer)
- 7 feet (84 in)
Correct answer: 6 feet 7 inches (79 in)
NEC 404.8(A) limits the center of the grip of the operating handle of a switch to not more than 6 feet 7 inches (2.0 m) above the floor or working platform.
Question 4: NEC 445.13 covers the ampacity of conductors from generators. Conductors from generator terminals to the first overcurrent device must have an ampacity of at least what percentage of the generator nameplate current rating?
- 100%
- 115% (Correct answer)
- 125%
- 150%
Correct answer: 115%
NEC 445.13 requires conductors from the generator terminals to the first distribution device to have an ampacity of not less than 115% of the nameplate current rating.
Question 5: Per NEC 517.13, patient care areas in health care facilities require a special grounding arrangement. What is the purpose of requiring both an insulated equipment grounding conductor AND a metallic raceway or cable armor in patient care branch circuits?
- To provide redundant grounding paths for safety-critical equipment (Correct answer)
- To reduce electromagnetic interference from medical equipment
- To comply with HIPAA electrical requirements
- To allow higher ampacity in the circuit
Correct answer: To provide redundant grounding paths for safety-critical equipment
NEC 517.13 requires both an insulated EGC and a metallic wiring method to provide two independent grounding paths, reducing the risk of ground faults in patient care areas.
Question 6: NEC 285.1 covers Transient Voltage Surge Suppressors (TVSS), now called Surge Protective Devices (SPDs). Per NEC 285.3, where are SPDs NOT permitted to be installed?
- On branch circuits over 1000V
- On feeder circuits in dwelling units
- On circuits exceeding 1000 volts (Correct answer)
- On ungrounded systems
Correct answer: On circuits exceeding 1000 volts
NEC 285.3 states that SPDs shall not be installed on circuits exceeding 1000 volts, as they are designed only for lower voltage applications.
Question 7: According to NEC 352.30, rigid PVC conduit (Schedule 40 or 80) must be securely fastened at specific intervals. What is the maximum spacing between supports for PVC conduit with a trade size of 2 inches?
- 3 feet
- 4 feet (Correct answer)
- 5 feet
- 6 feet
Correct answer: 4 feet
NEC Table 352.30 requires 2-inch trade size PVC conduit to be supported at a maximum spacing of 4 feet between supports.
