smokes on rcd

[lj.l]

Hi all

New here so hope this is in the right place.I'm just getting back into wiring houses after a couple of years off (due to housing slump).
In a two storey house does the interconnecter for the smoke alarms need protecting by a 30 ma rcd?
I didnt think that this was allowed.What is the best way around this seperate circuit on a rcbo?
Just want to know what everyone else is doing.
thanks

 

[peteludman]

the smokes dont have to be on rcd as long as cables are visable in trunking or in the right places(50mm below surfaces)of in earthed conduit etc.

 

[Mac]

I always put mine on a separate circuit and use an RCBO.Others may beg to differ,and welcome to the forum

 

[peteludman]

if rcd trips and batt runs out because you are away for few days how u gona know you got no smokes?
it is less likely to happen on mcb.

i know it never likely to happen and i would do it eather way (rcd or mcb)

 

[NoSparks]

Although you are allowed to run an LD2 (smoke detectors and heat rise detectors) on a seperate circuit, I personally believe they should be run off a frequently used lighting circuit, which is also permitted, for the reasons given above (noticing a fault). In all cases the wireing must be iaw the regs, so unless the rules for not using a 30mA RCD can be achieved, then one must be used. The requirement for a seperate circuit which I think you are refering to is for LB and LA circuits with a control pannel (where any fault would be signalled by the control pannel) and in this case the independance would not be satisfied by and RCD feeding other circuits, and so an RCBO would be appropriate.

Incidently you use the term "interconnect" this is the fourth core running between detectors not the whole circuit. Normally you would run a T&E to the first detector, then a 3 core & Earth between detectors.

 

[peteludman]

i agree with u

 

[Spudnik]

Local lighting circuit for me, which more than likely will have an RCD on it somewhere.

 

[lj.l]

Thanks for the welcome and views .
Felt a bit silly today when I checked the osg and it said to use a lighting circuit.
I always did use the upstairs lighting circuit ,I just got confused with the new 17th boards and the unprotected circuits .
Going to think up a new harder question .
Thanks again,

 

[supasparxs]

Hi all

New here so hope this is in the right place.I'm just getting back into wiring houses after a couple of years off (due to housing slump).
In a two storey house does the interconnecter for the smoke alarms need protecting by a 30 ma rcd?
I didnt think that this was allowed.What is the best way around this seperate circuit on a rcbo?
Just want to know what everyone else is doing.
thanks

I would class a Fire Alarm circuit as a special case and have it on a MCB,
just as a dedicated circuit for fridges and freezers and the compressors can trip RCD's and RCBO's

Richard

 

[aaronstuart]

Idealy yes put the smokes on the lighting circuit. But the problem lies that the smokes cant be protected by the same rcd that sockets are on. So if you've got dual rcd board with up and down ring on each side then the only option is an rcbo. Thats how I interpret it anyway.

Thanks Aaronstuart

 

[peteludman]

i supose you cant have the smokes on lighting circuit cos a blowing bulb can take out mcb and rcd to so it sounds best to have it own circuit

 

[NoSparks]

Yes, That is the whole point.

If the smokes are on the same RCD as some sockets, what will you do if the sockets (but more particularly the lights on that RCD) stop working. You'll get it fixed!

If the smokes are on an MCB or RCBO all on their own and they stop working, but everthing else is OK what do you do - 9 times out of 10 a customer won't even know, and even if they did they would probably ignore the problem.

Which do you think is best.