Smoke alarms withing a domestic property

[Dave301]

Ive been having a read in the electricians guide to the building regs with regards fire safety and a Grad D LD3 system, with regards the wiring of smoke and heat alarms it says on page 147 that alarms are required to:
b) be permanently wired with an independent circuit to the dis board or preferably supplied form a local regularly used lighting circuit.

Would any one be able to tell me why it would be preferable to be supplied from a local lighting circuit rather than having its own independent circuit? And in this case how would you go about isolation for it?

Thanks in advance

 

[telectrix]

i prefer using a local lighting circuit as it prevents tenants from switching off the breaker when they burn toast. there is no requirement for the smoke detectors to be isolated independently.

 

[Dave301]

thanks telectrix i actually just answered my own question by reading further. What would you do about isolation for said alarms then?

 

[telectrix]

nothing. if you need to remove or replace one, it's no big deal to isolate a lighting circuit for a short while. in fact, the heads can be removed/replaced without isolating anything as they just plug into the bases.

 

[Wilko]

I like to use a lighting cct as I feel a lighting fault doesn't get ignored for too long.

 

[telectrix]

I like to use a lighting cct as I feel a lighting fault doesn't get ignored for too long.

my sentiments eggsackly.

 

[Midwest]

Either install has its pros & cons, we've all seen the diy'er threads where they've tried to add a new luminaire, balleds it up, no lights and come here at the weekend asking how to get their lights back on!
I think those annoying beeps of the alarm batteries going flat are a good indication somethings amiss.
Incidentally, fitting one of those locator/tester switches for the alarms, in a domestic property is a must IMO, helps when testing & locating alarm that's indicating, in a houseful of alarms.