By the SightShield team · · 3 min read
The brain of the system
Every fire alarm system is built around a control panel. It powers the detectors and call points, watches them continuously, decides when there is a fire, sounds the alarms, operates other building systems and records every event. It also watches itself: a broken wire, a missing detector or a flat battery shows as a fault, so problems are found before a fire, not during one.
Zones and loops
| Term | Meaning | Used in |
|---|---|---|
| Zone | A group of devices wired together on one circuit; the panel shows which zone is in alarm | Conventional panels; also as display groups in addressable panels |
| Loop | A cable that starts and ends at the panel, carrying many individually addressed devices | Addressable panels |
| Address | A unique number for each device on a loop, so the panel shows exactly which one operated | Addressable panels |
| Isolator | A module that cuts off a short circuit so the rest of the loop keeps working | Addressable loops |
Conventional and addressable panels
Conventional panels are sold by the number of zones — 2, 4, 8, 16 and more. Each zone covers an area, and the panel shows only the zone. Addressable panels are sold by number of loops and devices per loop; each device has its own address and a text label such as “Ground floor store, detector 12”. Addressable panels cost more but suit larger and multi-floor buildings.
Conventional vs addressable fire alarms →Power supply and batteries
A fire alarm must keep working in a power cut. The panel has a mains supply and sealed backup batteries sized to run the system in standby for a set period and then sound alarms for a set time, as required by the applicable code. Batteries age, especially in Bangalore summers in hot electrical rooms, and should be tested and replaced on schedule. A low-battery fault on the panel should never be ignored.
Outputs that control the building
- Sounders and strobes: wired on separate monitored circuits.
- Door release: unlocks access-controlled doors and releases magnetic door holders on fire doors.
- Ventilation: shuts down AHUs or starts smoke extraction fans.
- Lifts: sends them to the ground floor in high-rise buildings.
- Public address: triggers recorded evacuation messages.
- CCTV and building management: signals the NVR or BMS so events are recorded and cameras called up.
Repeater panels and remote alerts
A repeater panel shows the same information as the main panel at a second location, such as the security gate, reception or a facility office. Many panels can also send alerts to phones through a GSM or IP communicator, so the owner or facility manager knows about an alarm or fault even when the building is closed — useful for warehouses, shops and offices at night.
Event log
Panels keep a log of alarms, faults, tests, silences and resets with date and time. The log is valuable for fault finding, for proving maintenance to insurers and inspectors, and for understanding what happened during an incident. Make sure the panel clock is set correctly and that the log is reviewed during maintenance visits.
Choosing the right panel
- Count devices and areas now, then leave spare capacity for future fit-outs and expansions.
- Choose addressable for multi-floor, large or complex buildings.
- Check the number of programmable relay outputs you need for doors, lifts, ventilation and CCTV.
- Ask whether the panel is supported locally for programming and spares.
- Place the panel where it is staffed around the clock, or add a repeater there.
Quick answers
What is the difference between a zone and a loop?+
A zone is a group of devices shown together on a conventional panel. A loop is a cable carrying many individually addressed devices on an addressable panel.
How long do fire panel batteries last?+
Sealed lead-acid batteries typically need replacing every few years, sooner in hot rooms. Test them during every maintenance visit.
What is a repeater panel?+
A second display that shows alarms and faults at another location, such as the security gate or reception.
Can a fire panel send alerts to my phone?+
Many panels can, with a GSM or IP communicator module.