Journeyman Electrician’s Exam Journeyman Electrician's Low Voltage Systems 2 — Questions and Answers
Question 1: NEC Article 760 covers the installation of wiring and equipment for which type of system?
- Emergency and standby power systems
- Fire alarm systems (Correct answer)
- Security and burglar alarm systems
- Nurse call and intercom systems
Correct answer: Fire alarm systems
Article 760 specifically covers fire alarm systems, including both power-limited (PLFA) and non-power-limited (NPLFA) fire alarm circuits.
Question 2: What does the cable designation 'FPLP' indicate on a fire alarm cable?
- Fire Protective Limited Power
- Fire Power Limited Plenum (Correct answer)
- Fireproof Power Line Protected
- Fire-Rated Power Loop Protected
Correct answer: Fire Power Limited Plenum
FPLP stands for Fire Power Limited Plenum, indicating the cable is listed for installation in air-handling spaces (plenums) per NEC Article 760.
Question 3: Non-power-limited fire alarm (NPLFA) circuits must be installed using wiring methods that comply with:
- NEC Article 725 Class 2 installation methods
- NEC Article 300 and applicable ampacity tables for power wiring (Correct answer)
- Only listed NPLFA cable installed exposed on surfaces
- PVC conduit exclusively for all building types
Correct answer: NEC Article 300 and applicable ampacity tables for power wiring
NPLFA circuits must follow Article 300 wiring methods since they are not power-limited and present shock and fire hazards similar to power circuits.
Question 4: Per NEC 760.49, what is the minimum conductor size for non-power-limited fire alarm (NPLFA) circuit conductors?
- 22 AWG copper
- 18 AWG copper (Correct answer)
- 14 AWG copper
- 12 AWG copper
Correct answer: 18 AWG copper
NEC 760.49 requires NPLFA circuit conductors to be no smaller than 18 AWG copper.
Question 5: Per NEC Article 760, what equipment requirement applies to all fire alarm system wiring and devices?
- Must be installed only by licensed fire alarm contractors
- Equipment and wiring must be listed for fire alarm service (Correct answer)
- All wiring must be enclosed in metal raceways throughout the building
- Only a dedicated fire alarm transformer may supply power to the system
Correct answer: Equipment and wiring must be listed for fire alarm service
Per NEC 760.1 and 760.3, all equipment and wiring used in fire alarm systems must be listed for that specific fire alarm application.
Question 6: When power-limited fire alarm (PLFA) cables are installed in an air-handling plenum space, which cable type is required?
- FPL
- FPLR
- FPLP (Correct answer)
- Any listed fire alarm cable is permitted in plenum spaces
Correct answer: FPLP
FPLP (Fire Power Limited Plenum) cables are required for installation in air-handling plenum spaces per NEC 760.154, as they must meet strict flame and smoke propagation requirements.
Question 7: Power-limited fire alarm (PLFA) circuit cables are permitted to be installed exposed on the surface of walls and ceilings provided they are:
- Enclosed in a listed raceway at all times
- Not subject to physical damage (Correct answer)
- No more than 10 feet in exposed length
- Separated from power conductors by at least 6 inches at all points
Correct answer: Not subject to physical damage
Per NEC 760.135, PLFA cables may be installed exposed on the surface of walls and ceilings as long as they are not subject to physical damage.
