Fire alarm system types
The automatic fire alarm system has (multi-wire) conventional alarm system, bus system addressable fire alarm system and two-wire bus system addressable fire alarm system. The difference is the connection mode of alarm circuit and power supply circuit of the equipment.
Multi-wire conventional fire alarm system
The (multi-wire) conventional fire alarm system refers to the detector (equipment) in each detection area, which is independent of the controller and has an independent signal loop. The signals in each detection area are input in parallel to the controller.
(Multi – wire) conventional fire alarm system is the point – to – point connection, the wiring is simple and it is the most reliable way.
The multi-wire system is suitable for the critical place with few alarming points and high reliability.
Advantage of (multi-wire) conventional fire alarm system:
Simple wiring and high reliability.
Need large amount of wire, construction and wiring are difficult.
Bus-line addressable fire alarm system
At present, most of the fire alarm control system adopts bus system. The signal lines of the two buses are composed of two wires, which are also responsible for the communication and power supply of detectors, manual alarm buttons and various modules (some components need separate power circuit power supply).
Each fire alarm controller can be connected to multiple bus loops.The wiring of bus system is simple and convenient.
Advantages of bus system addressable fire alarm:
Bus system wiring is simple and convenient, can access a large number of points. Can easy identify the alarm point.
The stability and reliability are lower than that of multi-wire system. In order to ensure the reliability, the linkage mode similar to multi-wire system is needed for some important equipment.
Two wire system
The two-wire system is further simplified on the basis of the bus system, and the signal transmission and power supply of all components are provided by a group of lines.
Advantages of two-wire system:
Cabling is further simplified than the bus system.
Shortages of two-wire system:
The stability and reliability are further reduced than bus system.