NICET Electrical Systems for Fire Protection 2 — Questions and Answers
Question 1: Which grounding requirement applies to fire alarm control equipment per NFPA 72?
- Grounding is optional for battery-powered systems
- Equipment must be grounded in accordance with NFPA 70 (NEC) (Correct answer)
- A dedicated grounding electrode is always required
- Equipment must be double insulated instead of grounded
Correct answer: Equipment must be grounded in accordance with NFPA 70 (NEC)
NFPA 72 requires fire alarm control equipment to be grounded in accordance with NFPA 70 (the National Electrical Code).
Question 2: What is the minimum standby battery capacity required for a fire alarm system per NFPA 72?
- 4 hours standby plus 5 minutes alarm
- 12 hours standby plus 5 minutes alarm
- 24 hours standby plus 5 minutes alarm (Correct answer)
- 48 hours standby plus 5 minutes alarm
Correct answer: 24 hours standby plus 5 minutes alarm
NFPA 72 requires fire alarm systems to have batteries capable of operating the system in standby mode for 24 hours followed by 5 minutes of full alarm.
Question 3: A supervised circuit in a fire alarm system detects which condition?
- Alarm conditions only
- Open circuits, short circuits, and ground faults (Correct answer)
- Voltage fluctuations above 10%
- Equipment temperature variations
Correct answer: Open circuits, short circuits, and ground faults
Supervised circuits continuously monitor for open circuits, short circuits, and ground faults, generating a trouble signal if any fault is detected.
Question 4: What is the maximum resistance allowed on a single initiating device circuit for most fire alarm systems?
- 10 ohms
- 25 ohms
- 50 ohms (Correct answer)
- 100 ohms
Correct answer: 50 ohms
Most fire alarm control panels specify a maximum loop resistance (commonly 50 ohms) for initiating device circuits to ensure reliable signal transmission.
Question 5: Under NEC Article 760, which installation method is NOT permitted for PLFA cables in ducts used for environmental air?
- FPL cable in metal conduit
- FPLP plenum-rated cable
- FPL cable exposed in plenum space (Correct answer)
- Wireways with FPL cable
Correct answer: FPL cable exposed in plenum space
FPL (standard) cables cannot be run exposed in plenums; only FPLP (plenum-rated) cables or cables in metal conduit are permitted in plenum spaces.
Question 6: What device protects a fire alarm control panel from voltage surges on incoming power lines?
- End-of-line resistor
- Transient voltage surge suppressor (TVSS) (Correct answer)
- Isolation transformer
- Ground fault circuit interrupter
Correct answer: Transient voltage surge suppressor (TVSS)
A transient voltage surge suppressor protects the fire alarm control panel from lightning-induced and other voltage transients on power and signal lines.
NICET Electrical Systems for Fire Protection 2
Which grounding requirement applies to fire alarm control equipment per NFPA 72?