Nest Protect Smoke Alarm Install Help

[Johnsmith5050]

Hello

I recently purchased a nest smart smoke alarm. I currently have 2 mains linked smoke alarms (one upstairs and one down). My plan was to replace the existing with the Nest versions.

The instructions seemed simple enough but when I have removed my existing alarm downstairs I ran into my first problem. It seems there are 3 sets of cable going into the existing terminal block (earth, live, neutral x3) and one interconnect cable. I was hoping someone could advise how this should be wired up? As the Nest instructions only describe if you have 2 of each connector and the terminal blocks they provide in the box only have space for 3 connections including to the alarm itself, which means there is an extra set of connections.

I believe current connection is taken from the lighting circuit if that helps. Attached picture of current wiring.

any help would be greatly appreciated.

 

[littlespark]

Looks like a looped feed in, looped feed out, then a 3 core linking this detector to the next. (Live, neutral and interconnect)

if there isn’t room in the new detector, the only option is a separate joint box up in the ceiling and bring the 3 core down.