Interconnected Fire Detectors Wiring Advice

[loonatic]

Hello,

Looking to install a number of wired interconnected fire detectors.

Do the units have to be daisy-chained together or can the circuit be split up using junction boxes?

Many thanks.

 

[DaftPunk]

It's fine to wire them daisy chained, star, or a combination of both. What ever suits the property best.

Try and avoid using junction boxes if you can and use the actual smoke alarms as your joints.

 

[PrenticeBoyofDerry]

I would recommend that you avoid any unnecessary junctions, stick to the daisy chain method.
As above any joint or junction, should be easily accessible for maintenance, inspection and test. Unless the joints are specially terminated and enclosed or MF boxes are used, this would then by in line with the requirements of BS7671.

 

[Gutterball]

use one of these in the ceiling http://www.screwfix.com/p/appleby-1...and you have a junction box behind the alarm http://www.aico.co.uk/what-works-where-electrical-wholesaler.html

 

[sparkwright]

I take it you are fitting mains powered interconnected smoke/heat detectors.

There shouldn't be any need for any joints, or even 'spurring' from a detector.

If running/fishing cables in an ordinary house, it is just as easy to run two cables rather than one.

Remember, you could have a very similar radio link system. Aico make these too. They only need a permanent live and neutral from nearest point on the lighting circuit - tradionally from the nearest ceiling rose.

These are good for old houses, but wouldn't bother with them if it's a new property being built where access to run wires isn't a problem.

 

[Gutterball]

you need to be sure that a permanent live is available at the ceiling rose not just a switched live. I went to a job a while back and the client was complaining that there was something wrong with the smokes because the battery's were not lasting. I discovered that they were connected to a switched supplied rose so were only getting powered when the light was on.