simple question

thekingiam · May 15, 2014

can i feed fire mains powered fire alarms from emergency light fittings which have overide switch for testing lights.
they will have battery backup on alarms so any tests of lights battery should kick in.

thekingiam · May 15, 2014

must be too simple of a question?
what is the circumfrunce of the planet earth in mm

telectrix · May 15, 2014

can't see why not. you have a permanent feed except when the keys are operated for testing. however, there may be a reg. in bs5839 or 5266 that says NO.

thekingiam · May 15, 2014

hmm haven't got those regs, can't see a problem either though as at least i am improoving installation as it has no fire alarms at present.

Andy78 · May 15, 2014

I would probably do it if I had to. I would exhaust all other possibilities of sources of supply first though.

telectrix · May 15, 2014

oh, and the circumference of the earth in mm is around 15billion, but varies according to temperature, moon gravity, atmospheric pressure, and a few other factors. there is an equation, if you want a more accurate value.

[ElectriciansForums.net] simple question

Silly Sausage · May 15, 2014

telectrix said:
View attachment 24686

42 - Video - Numberphile - Videos about Numbers and Stuff

tazz · May 15, 2014

As long as the are for Grade D installation (ie mains with battery backup) then the supply can be taken off the lighting circuit, which would include EM fittings.