Smoke alarms

deandean

I'm looking at putting in a couple of mains + battery smoke alarms to replace my battery-only ones.

Can they be powered from the lighting circuit (easy job) or do they now need their own MCB and circuit (big job)?

Can't find anything on this on the web.

Thanks.

Risteard81

You might like to look at IS 3218 and also BS 5839-6. (I am assuming that it is Domestic detection you are referring to.)

Basically the preference is for it to be fed from a regularly-used local lighting circuit so that it is quickly noticed if the circuit is de-energised.

However they will all need to be on the same circuit unless you have used radio links between them.

This must also be certified for the Grade and Category of detection, e.g. Grade D, Category LD2.

As usual, the best advice is to get a Registered Electrical Contractor to install the system.

deandean

Many Thanks Risteard.

I looked over those references, I may as well go the whole hog and bring the house up to 'spec. So it'll be more like six smoke alarms for me.

Stoner

deandean wrote:

I looked over those references, I may as well go the whole hog and bring the house up to 'spec. So it'll be more like six smoke alarms for me.

You coujd look at getting them on your intruder alarm too.

The Ayatolla

Thinking of sorting this myself as well.

What are the regs in relation to minimum amount in a house?

Was thinking one in living room, one in the hall downstairs, one in the landing upstairs and a heat detector in the kitchen. All looped off the same supply from the fuseboard.

Risteard81

The Ayatolla wrote: »

What are the regs in relation to minimum amount in a house?

A new house must have at a minimum a Grade D, Category LD2 system. Look at IS 3218 for further information on this. (Also Technical Guidance Documents on the Building Regulations.)

Irish Steve

Used to be the case that Smoke detectors could be obtained that worked off the 12V DC supply in the alarm panel, which has 2 advantages, the first is that they are still powered if the main power fails, and the second is that if a detector is activated, the alarm is also triggered, which means even more noise over a wider area. Very helpful if the smoke detector is remote, like a garage, or at the other end and another floor of a large house.