Replacing old Alarms With Interconnected Smoke Alarms Ask questions and find answers to many subjects relating to electrics and electrical work

[johnuk40]

Hi i was wondering if anyone could tell me if my existing smoke alarms could be replaced with interconnet smoke alarms .
The main smoke alarm situated on living room ceiling has 5 wires coming through ceiling 2 red
( joined together ) , 1 yellow ...... and 1 blue and 1 black ( joined together )
The upstairs landing has only 3 wires coming from ceiling , 1 red , 1 yellow , and 1 blue .
Im assuming that both the smoke detector wirings have been taken from the light fittings .
Any advice would be appreciated , many thanks John

[stoneyboy]

Hi johnuk40
It is possible that the yellow wire is an interlink cable but you would need to check this yourself or get someone in to identify it’s purpose.
If this is not an interlink cable you could always fit smart rf alarms which do link wirelessly.
Regards S

[chriscba]

I take it you want to replace your mains smoke alarms with wireless interconnected alarms.
I presume they will be battery powered, so you will have to find out where your first alarm is fed from, probably a light fitting near by, it will have to be disconnected (live & neutral & earth)& made safe. You can poke the cables into the ceiling.
The second alarm would have been fed from the first with a 3 core cable, should be dead as the first was disconnected, however, it should be tested.

[johnuk40]

Hi Stoneyboy , is it possible to tell me how i check both the Yellow cables to identify if this is the interconnect cable, i will try and add a couple of images , should i just wire them up the same way as my existing detectors and set them off to see if both activate ( cant upload pics , sorry )

[stoneyboy]

Hi johnuk40
If your existing alarms are connected using the yellow cable you should be able to establish its purpose by looking at a wiring diagram for the existing ones. If it is not marked on the existing alarms do a search on line for your particular model.
Regards S

[Mr White]

johnuk40 (I did not see any mention of you wanting to use radio interconnected smoke alarms.) As interlinked mains smoke alarms should use a 3 core and earth just as your existing ones have, I would say all you need to do is change them and connect them as they are now. (Live, Neutral and Interlink)

Do use the same brand of detector (Your choice) and change them both before you turn the mains back on.
You might also want to write the date you install them on the battery (If it is replaceable)

If in doubt get a competent person to do the job for you.