In article ,
John Rumm wrote:
On 14/06/2015 13:55, Bob Eager wrote:
On Sun, 14 Jun 2015 05:20:35 -0700, spuorgelgoog wrote:

On Sunday, 14 June 2015 13:03:03 UTC+1, John Mulrooney wrote:
I'm starting to install some interlinked smoke and heat alarms. Can
they use L & N from different circuits, or sgould they have a
seperate dedicated one.

All alarms must be on the same circuit.

It doesn't have to be a dedicated alarm-only circuit and there are
good reasons for it not being so; but the alarms should then have
battery or capacitor back-up.

On a mixed use circuit you are likely to notice a supply failure more
quickly than if only the alarms are affected.

Or do what I do and put a prominent non-maintained emergency light on
the same circuit. Useful in its own right.

Yup that was my preferred solution as well. I also fitted a centralised
switch so that the alarms can be tested or silenced from one place
easily (since some are well out of reach on 10' high ceilings)

Thanks all inc. Tim & Adam, got the idea

John

--
John Mulrooney
NOTE Email address IS correct but might not be checked for a while.