Smoke alarms wiring

[Gerry Savage]

hi guys need a bit of insight here. Wiring up mains smoke alarms and interlinking with heat detector in property. Came across a bit of a grey area with legislation. Now I know it can be wired on its own circuit or on with an existing lighting circuit but I can't find anything telling me if the supply to the first smoke alarm has to be wired from the lighting circuit breaker at consumer unit or if I can tap off a light/switch with a permanent live and neutral. Will make a big difference as the cu is a nightmare to get cables to!! Any help will be much appreciated. Cheers

 

[Richard Burns]

So long as it is powered from the lighting circuit where it is connected is immaterial.
Obviously on its own circuit is from the board but if you are powering from the lighting circuit you could power each one from a light local to the alarm (each light would need to be on the same circuit unless using wireless interlinks); you would still need to run an interlink between each alarm so it wont help much.

 

[tazz]

Grade D does not require a dedicated circuit, as above powered from the lighting circuit meets BS5839 part 6