smoke alarms

[electrified]

Need to wire two mains interlinked smoke alarms. Split load rcd board however i believe smoke alarms have to be on their own not rcd protected especially away from rcd that covers socket outlets. But i was wondering if i could take a feed from lighting circuit that is protected by an rcd to my smoke alarm then a 3 core+earth to other smoke alarm, because regs say you can do this.

 

[markyd1]

Why do believe that? What type RCD?

 

[electrified]

ac

 

[markyd1]

Will need changing if its type AC

 

[flameport]

if i could take a feed from lighting circuit that is protected by an rcd to my smoke alarm then a 3 core+earth to other smoke alarm,

Yes, that is the usual method.

The cable will very likely mean an RCD is required.
The smoke alarms themselves do not, but doesn't matter if they have one.

 

[electrified]

Yes, that is the usual method.

The cable will very likely mean an RCD is required.
The smoke alarms themselves do not, but doesn't matter if they have one.

Ah so i can take a feed from lighting jb and loop the alarms with 3 core, i did see something about smoke alarms being able to be “isolated” without turning off the lighting circuit however does this necessarily mean a switch? because they do technically get isolated when you untwist the smoke alarm from the ceiling.

Thanks

 

[markyd1]

Yes but the base is still live! so how is that isolating

 

[electrified]

Yes but the base is still live! so how is that isolating

i’m talking about isolating the smoke alarm not the circuit. why does the rcd need changing if it’s an ac?

 

[flameport]

does this necessarily mean a switch?

No, a switch is not required and not desirable either.
If it's the Aico alarms, removing it from the base is the isolation.
Other less useful brands may be available.

 

[markyd1]

Adding accessories to a circuit.....RCD needs changing to type A, Amendment 2