Smoke alarm.. Help

[Yesyes]

Hi guys,

I'm wiring my brothers house and have a slight problem. I was intending on linking the smoke and heat detectors. However, instead of using a 3 core to the last detector a 2 core and earth was put in instead. The walls and ceilings have been plastered and my two options now would be to either have three of the detectors interlinked and one stand alone or use the earth wire as the interlink/neutral line to pick up the last detector so that they are all on one circuit... What would you advise?[/b]

 

[Risteard]

No you most certainly cannot do that. What about a radio base?

 

[deadshort]

Hi, radio linked are very reliable, i have installed dozens.


DS

 

[Yesyes]

Only want to use Radio link bases as a last resort.
Are there any other options available?.. Bit of a cock up really. I can link hallway, landing and kitchen heat and have the detector in the living room ( large extension) on its own.... What dya think?..

 

[sparkwright]

Another vote for the radio link bases - they are very good. Aico perhaps the best.

You don't give details how the current cable is installed. Is a case of lifting a few floor boards, and taping the new cable to the old cable, and pulling it through?

Or can you 'fish' a new cable through most of the ceiling void?

You can't have a detector unlinked to the others; and you can't use the earth wire.

I take it is an actual requirement to have this detector in the extension?

 

[PrenticeBoyofDerry]

What would you advise?

As already mentioned RF bases, you will need two. One at any one of the linked alarms and one at the standalone one. House code and job done. You should not use the CPC, as anything other than a CPC.

 

[Yesyes]

Thanks for reply.
It's not a requirement but it is quite a large extension and was planning to put one in.
The detector in this room will be the last on the circuit. The detectors I was intending on using are aico and there is no terminal for the earth wire. It will be terminated in a connector block.
There is no way of getting a cable there. Basically I was hoping to utilise the 2 core and earth cable.

 

[PrenticeBoyofDerry]

Aico generally have an earth terminal.
It is simple to add two RF bases to the aico alarms, why do you have an issue with this? Only other solution is to replace t&e for three core and earth.
I recall the regs state that each accessory should have a CPC present, so using CPC as a neutral link between the other three units and this one, would not be compliant.

 

[sparkwright]

The Aico ones certainly should have an earth terminal, though they are made in such a way it could have dropped out.

Why not go for the radio link bases?

Why aren't you keen on them?

As said, you only need two.

It will solve all your problems.

 

[Yesyes]

Guess radio bases it is then.
I'll wire the circuit in 2 core t+e.
My bro's missus is a pain in the ass and didn't want them, she wanted them hard wired but hey ho.

Thanks again for replies

 

[ban-all-sheds]

If you can replace the cable and use a hard wired interconnect then go for that - wireless (anything) is not to be preferred over wired, all other things being equal.

But if they are not equal, and you can't replace the cable, you'll have to use wired.