Smoke detector wiring?

[Roger465]

Actually, now that I’ve removed the ceiling plates, it all looks very simple, as you said. On each little 3-pin socket which the old detectors plug into, there’s live, neutral, link (or whatever it’s called) from left to right – so it should just be a question of snipping the sockets off, and connecting the appropriate wires to the new units…

 

[Taylortwocities]

I Would unplug the old alarms and then do a continuity and insulation resistance test on the whole circuit.
Then you'll know it's all ok to connect up.

The fuse in the fuse box may have been removed for a reason!

 

[Roger465]

I Would unplug the old alarms and then do a continuity and insulation resistance test on the whole circuit.
Then you'll know it's all ok to connect up.

The fuse in the fuse box may have been removed for a reason!

Now that I WOULD need a spark for

 

[Taylortwocities]

Surely that is what anybody would do?
Without testing you are just heading down the *bang* test route. Just connect it up, switch on, and hope that it works.
Not the best way. You might even create a fire that your alarms on that faulty wiring will not detect!