F80 F80 Code Requirements 3 — Questions and Answers
Question 1: What is the maximum allowable voltage drop on a fire alarm initiating device circuit (IDC) under NFPA 72?
- 1 volt
- 2 volts (Correct answer)
- 3 volts
- 5 volts
Correct answer: 2 volts
NFPA 72 limits voltage drop on initiating device circuits to no more than 2 volts to ensure proper device operation.
Question 2: According to NFPA 72, in which occupancy type must all corridors be equipped with smoke detectors as a minimum requirement?
- Assembly occupancies
- Business occupancies
- Health care occupancies (Correct answer)
- Mercantile occupancies
Correct answer: Health care occupancies
Health care occupancies require smoke detectors in all corridors due to the higher life-safety risk for occupants who may not be able to self-evacuate.
Question 3: Under NFPA 72, what is the required minimum wire gauge for a Class A fire alarm circuit?
- 18 AWG (Correct answer)
- 16 AWG
- 14 AWG
- 12 AWG
Correct answer: 18 AWG
NFPA 72 requires a minimum of 18 AWG conductors for fire alarm circuits; the manufacturer's listing may require larger gauges.
Question 4: A Class B initiating device circuit (IDC) differs from a Class A IDC primarily because Class B circuits:
- Require end-of-line resistors and do not provide fault detection beyond the first open (Correct answer)
- Operate at higher voltages
- Must use shielded cable throughout
- Support twice as many devices
Correct answer: Require end-of-line resistors and do not provide fault detection beyond the first open
Class B IDCs use end-of-line resistors for supervision but lose contact with devices beyond an open fault, unlike Class A circuits that loop back.
Question 5: According to the F80 code framework, which document must be submitted to the Authority Having Jurisdiction (AHJ) before fire alarm system installation begins?
- Certificate of occupancy
- Shop drawings and specifications (Correct answer)
- Manufacturer's maintenance manual
- Inspection and testing report
Correct answer: Shop drawings and specifications
Shop drawings and specifications must be submitted to and approved by the AHJ prior to installation of a fire alarm system.
Question 6: NFPA 72 requires that the primary power supply for a fire alarm system be:
- A dedicated branch circuit rated at 120V from the main electrical panel (Correct answer)
- Any available 120V circuit in the building
- A UPS system with 72-hour capacity
- Solar power with battery backup
Correct answer: A dedicated branch circuit rated at 120V from the main electrical panel
The primary power supply must be a dedicated branch circuit, typically 120V, connected ahead of any local disconnecting means and clearly labeled.
Question 7: Under F80 code requirements, what must be done when a fire alarm system is out of service for more than 8 hours in a 24-hour period?
- The AHJ and the building owner must be notified only
- A fire watch must be established and the AHJ notified (Correct answer)
- The building must be immediately evacuated
- A temporary sprinkler system must be installed
Correct answer: A fire watch must be established and the AHJ notified
When a fire alarm system is out of service for more than 8 hours, a fire watch must be established and the AHJ must be notified per NFPA 72 and IFC requirements.
F80 F80 Code Requirements 3
What is the maximum allowable voltage drop on a fire alarm initiating device circuit (IDC) under NFPA 72?