Smokes?

[blackiel]

Sharing circuits is asking for Grief later on,put them on their own cct,no call backs...

 

[jase]

Just wired a HMO myself and standard interlinked smokes were unacceptable to the council and fire officer.

Full risk assesment was required and ended up putting in a level 1 grade a system to keep all parties happy!

3 Storey student house with 6 double bedrooms which makes a significant difference.

gonna be a spaz here but it's late and buggin me, HMO ?

 

[cbw]

House of multiple ocupancy.

I cannot recal exactly how its defined but someting along the lines of a house with more than 2 residents from 2 or more different families?

It does vary what you read......

 

[RexT]

Hi guys,

It is an interesting point re the smoke alarms as to whether they should be installed on their own circuit or not. From what I have seen so far it is a matter of choice as it appears there is leeway in the standards. I believe BS7671 says that a safety circuit is to be dedicated ie on its own circuit (from memeory sorry I havent got the book to hand) and then there is the look at BS5839 part 6 bit giving you the option of how it is connected etc.

I believe the comments above made about the systems houses is correct in that this is considered (or was) the most reliable control method of the supply.

It never hurts contacting the local building control guys or who will be enforcing it and see if they have a take on it or not.

Hope this helps,

Best wishes

Rex

 

[Risteard]

The On-Site Guide specifically states that it may be desirable to use a local readily-used lighting circuit (for reasons already mentioned).

 

[Spudnik]

I think safety circuits are classed as those that are for designated fire detection systems rather than domestic smokes.

 

[RexT]

Hi Risteard,

Thanks, sounds very sensible and reasonable. It is always best to be on the side of safety and I guess the reliability of a circuit is important when considering the safety.

Of course it is the battery backup bit that is important in that if the circuit is de-energised due to causes by other products then you are reliant on this.

Thanks again,

Best wishes

Rex

 

[rocker]

Well they all went in alright. One thing though, there wasn't any directions re size of cable to use to interlink them.... I imagine alarm cable or bellwire would be OK but used a load of 1.5mm single to be on the safe side. What should I be using?

 

[DurhamSparky]

1.0 / 1.5

 

[rocker]

Nice

 

[robsparky1975]

These are wired in 1.0mm/1.5mm 3 core + earth,are they 240v?,ive put a lot in council flats/houses one in every habitable room, sometimes 8 in a house,used to pick up from local lighting circuit, and fit keyswitch next to detector for isolation of smokes,this was what niceic man recommended,but on new build i put on own circuit,yes rcd protected,if memory serves 17th edition,labc and bs5839 do not give a diffinative answer to what way it should be done,so many different forms of guides and people sticking there bit in why cant these people come up with a guide on how they want these things put in,the regs are almost like egyptian at times as one thing contradicts another.sorry i went off on one there.

 

[chris gray]

http://www.sensotec.co.uk/sfs/PDFS/MICROFIRE.pdf
we fitted one of these systems the other week in a hmo, pretty good actually.
heads in 3core t+e and the call points in 2core t+e.
we never use a designated circuit.

on a side not are you required to over sleeve the interlink cable? i dont see why you would tbh.

 

[rocker]

on a side not are you required to over sleeve the interlink cable? i dont see why you would tbh.

I didn't sleeve, I used yellow single, labelled at each end.

 

[chris gray]

I didn't sleeve, I used yellow single, labelled at each end.

think you may of missed my point mate.
if youre wiring smokes using 3core+e using the black as the interlinking core would you be required to over sleeve that?

 

[rocker]

Ah I see. I wouldn't know what to sleeve them in.... I'd probably use good old white tape and just label them up at each end.