sprinkler system feed into main switch... hmmm

fylthespider · Oct 16, 2012

Hi chaps,

come across interesting one whilst sorting another problem out.

modern three phase board in a small private care home. (i was checking why the spa rcd was tripping)

Took the cover off the main switch ( to check Ze) and found a 1.5mm fp200 cable connected to one of the incoming phases. This is then feeding 13a fused spur (outside main C.U) which then feeds to sprinkler system control unit.

owner said company that installed sprinkler system did it (cos they have to have an un-fused supply) and they are responsible for maintainance, certification, etc.

now, its not my problem, but it doesn't sit right with me.
we've got about 1m of 1.5mm fp200 hanging on the 100A incoming main cutout fuse.
even tho its all enclosed within a metal clad CU, surely this carn't be right?

I know sprinklers are a law onto themselves but this certainly contravenes 17th and common sense.

Going to ring tech help (napit) tomorrow but any thoughts/info on sprinkler systems would be appreciated.

Yours, (not sure if going on war path or not)
phil.

snowhead · Oct 16, 2012

It's correct that how sprinklers are done, to stop anyone accidentally turning them off.
Can't tell you how its exempted from the regs tho'.

telectrix · Oct 16, 2012

if they need an unfused supply , as they say, then they have defeated their objective by fitting a 13A FCU. anyone can remove the fuse.

fylthespider · Oct 16, 2012

the fuse thing did fox me cos, yes that fuse could blow. would have thought a type c 16A mcb would at least give some protection. but if thats how its done, who am i to question?
would love to know how its exempt, might be useful in other 'difficult' situations.

living, learning and getting less sure what the hell is the right way to do owt day by day.

cheers.

Rockingit · Oct 16, 2012

fylthespider said:
the fuse thing did fox me cos, yes that fuse could blow. would have thought a type c 16A mcb would at least give some protection. but if thats how its done, who am i to question?
would love to know how its exempt, might be useful in other 'difficult' situations.

living, learning and getting less sure what the hell is the right way to do owt day by day.

cheers.

110.1.3 "The Regulations are intended to be applied to electrical installations generally but, in certain cases, they may need to be supplemented by the requirements or recommendations of other British or Harmonised Standards or by the requirements of the person ordering the work"