Fire Alarm system

[PeterPan27]

Hi people

Sorry for my lack of knowledge.

Just wondering how a fire alarm system would be fitted?

Type of cable = FP200???

MCB type ??

Cable size?

Sorry if its a stupid question..

Thanks all x

 

[tazz]

Power to the panel is in enhanced cable 1.5mm 2 core + E (FP200 enhanced or pyro) to a local lockable, double pole, switched fused spur, then feed to panel
cable to circuits/zones is 1.5mm FP200 2 core + E
Cable to Bell circuits is 2.5mm 2 core + E FP200 (most sirens are such low current today that 1.5mm is used)

Hopes this gives you the info needed for you college work

 

[PeterPan27]

thanks mate

 

[Guest154]

is this correct tazz can break glasses and detectors be on the same circuit and sirens on a different circuit or is it the other way about , cheers

 

[tazz]

Call points and detectors and sirens can all be on the same circuit, as long as the installation conprises of 2 or more zones.

 

[Guest154]

cheers i have only fitted 2 or 3 fire alarms but my old mentor always put call points and detectors on one circuit and sirens on another or it would not work her said

 

[tazz]

No hes doing it the right old way detection on one circuit bells on the other, but technology changes and bells can now be put on same circuit, on conventional and addressable systems. This is the reason bells and sirens are polorised these days ie the is a diode in the circuit most systems change polarity on activation triggering the bells/sirens

 

[Stroppy]

A while ago I caught my colleague disconnecting and throwing away the diode from detector bases. Couldn't get a straight answer out of him why!

 

[tazz]

A while ago I caught my colleague disconnecting and throwing away the diode from detector bases. Couldn't get a straight answer out of him why!

Different senario with detectors, its a different type of diode, and is there to show when a detector has been removed from the base, so without it the panel will not show fault, and can prevent and other detectors working....not a good idea to remove...!!