Conventional Fire Alarm System Working Principle

[Abhi]

Hi,

I wanted to know how the conventional FAS work, meaning how the detectors & controller communicate with each other and how controller understand that the detector is in fire mode (in case of fire detection)? lastly why the End Of Line resistor is used?

Awaiting for the precious guidance!

[kurnal]

http://www.gcg-es.com/Principals%20Products/8%20-%20Morley-AIS/Morley%20AIS%2002%20-%20Fire%20Detection%20Systems%20Guide.pdf

[jackbrouno]

This was helpful and informative, thanks for the share

[Psuedonym]

Notifier do a guide called The Little Black Book. It's available as a download or hardcopy which they post to you and it's FOC. Its good and informative but leans toward a product sales guide too. Have a look on their website for details. 

[Wiz]

Abhi, a very basic explanation is that the control panel is monitoring the current drawn from the zone circuit to determine the status of that zone. The end-of-line resistor draws a known current, and so the control panel recognises that if the level of current being drawn is lower than that expected to be drawn by the end-of-line resistor it displays an open-circuit fault condition. When a detector or manual call-point is operated, the level of current drawn increases above the level expected to be drawn by the end-of-line resistor and therefore the control panel will display a fire condition.
The term 'conventional' which you use, and which should more properly be called non-addressable, covers a whole range of technologies and operating systems which may operate differently from the above, but the explanation covers the basic principles of systems using a standard end-of-line resistor set-up.