Mains smoke alarms [linked]

[foxhole]

Have wiring in for three smoke/fire detectors which will be linked , need to close up the ceiling soon [plasterboard it]. Currently have twin and earth from top landing and bottom of stairs run thru to the kitchen where third fire alarm sensor will be [and pick up the lighting circuit for power] , can the wiring be connected externally to the smoke sensors or does it have to run from one to the other [radial type].

 

[Iggifer]

They need to be run from one point, to the next, to the next etc.

But I have some bad news for you, you use 3 Core + Earth to interconnect smoke alarms. You only use twin and earth from the supply to the first point, then 3C+E onwards along the circuit, as you need L+N+SL+E

 

[foxhole]

Thanks, but that's contrary to the info I received on this forum from others and from the manufacturer.?

 

[flameport]

Instructions: http://www.aico.co.uk/How-do-I-wire-hard-wired.html
3 core & earth is required, same for other manufacturers.

If using radio link bases then you can use T&E, but that will cost far more and no point at all if you are installing new wiring anyway.

 

[sparkwright]

Another vote for 3 core+E.

What info did you receive on this forum then?

3 core+E, BTW, consists of brown, black, grey and bare earth.

 

[Iggifer]

I would also be interested to see any advice from a mfg that said use T+E, unless it's Nest smokes, which are radiolink as standard, and therefore just need the L+N supply.

 

[333rocky333]

//www.diynot.com/diy/threads/mains-smoke-and-heat-detectors.448785/

 

[Iggifer]

I'm not going through 16 pages! I remember posting in the thread, wasn't that the HMO one?

The very first reply from Echo says 3C+E so.....

 

[foxhole]

Seems I missed that, 38 replies, seems to have started an argument, seems electrician like to argue? ) Instruction manual from Kidde only shows three terminals, no earth.

 

[Iggifer]

Let's see the advice from a manufacturer that says twin+earth then.....

 

[EFLImpudence]

seems electrician like to argue?

No, we don't.

 

[Iggifer]

seems electrician like to argue?

No, we don't.

Yes. We do

 

[sparkwright]

//www.diynot.com/diy/threads/mains-smoke-and-heat-detectors.448785/

Hmmm. I hope he read RF's comment CAREFULLY on page 3...

 

[sparkwright]

seems electrician like to argue?

No, we don't.

Yes. We do

We do not.

 

[sparkwright]

Seems I missed that, 38 replies, seems to have started an argument, seems electrician like to argue? ) Instruction manual from Kidde only shows three terminals, no earth.

If no earth, but still three terminals, then you need 3 CORES, and you still connect the bare (but sleeved) earths together.