Hardwired smoke alarm

[an203888]

No problem. I will stick a hardwired system in.
Looking at instructions for a couple of models, it's acceptable to wire them into the lighting circuit?

 

[JohnW2]

No problem. I will stick a hardwired system in. Looking at instructions for a couple of models, it's acceptable to wire them into the lighting circuit?

As I understand it, yes - but the 'requirement' is that they should all be wired into the same lighting circuit. That means that if (as is usual) there are two or more lighting circuits (e.g. upstairs and downstairs), one cannot necessarily just feed each one from the nearest convenient part of one or other of the lighting circuits - and that remains true even if the interconnections between alarms is wireless. If the interconnection is hard-wired, then the natural think to do is to join all the alarms with 3-core (plus earth) cable as a 'daisy chain' and then connect to the power source (lighting circuit or dedicated circuit) in just one place.

Kind Regards, John