Interlink smoke alarm question

[Edufixer]

I have just replaced one smoke alarm in our house which is mains wired and interlinked with upstairs. However, the linked 'granny annex' alarm does not link with the main house. I have been advised that all three should be linked to each other.
Is this true as the annex is on its own circuit
Is it a simple case of connecting main house to annex?
Advice would be useful

 

[Taylortwocities]

Should be linked. I am sure that granny will want to know that the main house is on fire, and you might want to know about her bit too!
The annex alarm will be powered from the other alarms in the main house.

 

[Edufixer]

Fair point. Annex currently on own circuit for power so 3 core e from nearest house fire alarm to annex and remove annex power supply to alarm?

 

[Taylortwocities]

Yes

 

[Edufixer]

Thanks

 

[mwatsonxx]

Commercially that arrangement would be unacceptable unless interface units were installed in both premises.

Also do the premises have separate power supplies? If they are separate, indication should be provided warning that fire detection power supply is from the main building.

 

[Edufixer]

Domestic dwelling. House and annex run of one power supply. Annex smoke alarm on annex rcd, 2 others on house rcd. Would ypu suggest another fix?
Thanks

 

[mwatsonxx]

Domestic dwelling. House and annex run of one power supply. Annex smoke alarm on annex rcd, 2 others on house rcd. Would ypu suggest another fix?
Thanks

So in reality it is one premise.

Annex currently on own circuit for power so 3 core e from nearest house fire alarm to annex and remove annex power supply to alarm?

As TTC had advised, that will be ok. I was only questioning whether it was one or two premise.

 

[Lectrician]

I would wire the two sides independently, but link them with a pair of wireless bases. Aico are perfect for this.

 

[Edufixer]

Thanks lectrician, exactly what I did yesterday, too difficult to run 3 & e to annex due to fire wall in loft space. So all now working.