AK Fire Alarm flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Addressable System
- A fire alarm system in which each initiating device and notification appliance has a unique digital address, allowing the control unit to identify the specific device in alarm or trouble.
- Conventional Zone System
- A system where multiple devices share a single circuit, so the control unit reports only the zone in alarm rather than the individual device that initiated the signal.
- Supervisory Signal
- A signal indicating an off-normal condition of a system or device that is not a fire alarm, such as a closed sprinkler control valve or low air pressure.
- Positive Alarm Sequence
- An NFPA 72 feature allowing up to 15 seconds for alarm verification and 180 seconds total for investigation before notification appliances activate, requiring trained personnel.
- NFPA 72 Scope
- The National Fire Alarm and Signaling Code governs the application, installation, location, performance, inspection, testing, and maintenance of fire alarm and signaling systems.
- NEC Article 760
- The National Electrical Code article covering fire alarm systems, establishing wiring methods, power-limited classifications, and conductor requirements for fire alarm circuits.
- Class A Circuit
- A supervised circuit that includes a return path to the control unit, so a single open or break does not prevent operation of devices beyond the fault.
- Alaska Fire Code Adoption
- Alaska adopts NFPA 1 and NFPA 101 with state amendments; local jurisdictions may impose additional requirements stricter than the statewide minimum.
- Photoelectric Detector
- A smoke detector that responds to visible smoke by detecting light scattered or obscured by smoke particles, effective for smoldering fires producing larger particles.
- Ionization Detector
- A smoke detector that responds to products of combustion by measuring changes in ionization current, effective for fast-flaming fires producing smaller particles.
- Manual Pull Station Height
- Manual fire alarm boxes must be mounted so the operating handle is 42 to 48 inches above the finished floor, typically within 5 feet of an exit.
- Duct Smoke Detector
- A detector installed in an air-handling duct that samples airflow to detect smoke; required where air-handling systems exceed 2,000 cfm and serve multiple floors.
- Temporal-Three Signal
- The standard evacuation signal pattern of three audible pulses, a pause, three pulses, a pause, three pulses, then a long pause, repeated continuously.
- Public Mode Audibility
- Notification must produce 15 dBA above average ambient or 5 dBA above maximum ambient, whichever is greater, measured at 10 feet from the appliance.
- Strobe Mounting Height
- Visible notification appliances must be mounted 80 to 96 inches above the finished floor, or within 6 inches of the ceiling, whichever is lower.
- Sleeping Area Audibility
- In sleeping areas, notification must produce 75 dBA at the pillow or 15 dBA above ambient, whichever is greater, to reliably awaken occupants.
- Battery Capacity Formula
- Required ampere-hours equal standby current times standby hours plus alarm current times alarm minutes divided by 60, with a 1.2 derating factor applied.
- End-of-Line Resistor
- A resistor installed at the last device on a Class B supervised circuit that allows the control unit to detect opens and shorts in the wiring.
- NAC Voltage Drop
- The voltage lost along a notification appliance circuit, calculated as twice the current times resistance times length, keeping the last appliance above its listed minimum.
- Secondary Power Requirement
- Batteries or a generator must supply 24 hours of standby followed by 5 minutes of alarm, or 15 minutes for voice evacuation systems.
- Alarm Processing Time
- The fire alarm control unit must activate notification appliances within 10 seconds of receiving an alarm signal from an initiating device.
- Trouble Signal Annunciation
- A trouble condition must annunciate audibly and visibly at the control unit within 200 seconds of the fault, distinct from alarm and supervisory signals.
- Digital Alarm Communicator
- A transmitter that sends signals to a supervising station over telephone or network paths; two distinct transmission paths are required for reliability.
- Remote Annunciator
- A unit located away from the main control panel that displays alarm, trouble, and supervisory status by zone or point and must be supervised against faults.
- Smoke Detector Sensitivity Test
- Detector sensitivity must be checked within one year of installation and every two years thereafter, or per manufacturer's published instructions.
- Battery Load Test
- An annual test discharging the battery to verify capacity; batteries are replaced when capacity drops below 80 percent of the rated ampere-hour capacity.
- Inspection Versus Testing
- Inspection is a visual examination without operating the device; testing verifies functional performance; maintenance restores or replaces deficient components.
- Record of Completion
- An NFPA 72 form documenting the installed system description, device inventory, and certifications signed by the installer and the authority having jurisdiction.
- Sequence of Operations
- A matrix defining cause-and-effect for each initiating zone, specifying which outputs activate, which systems shut down, and any time delays.
- As-Built Drawings
- Drawings reflecting the actual installed condition of the fire alarm system, updated after any modification and retained for inspection by the authority.
- Plenum-Rated Cable
- Fire alarm cable installed in air-handling plenums must be listed as plenum-rated (FPLP) with low smoke and flame spread characteristics.
- Power-Limited Separation
- Power-limited fire alarm conductors must be separated from non-power-limited conductors by at least 2 inches or a listed barrier per NEC 760.