Smoke Alarm

Mr_love_monkey · 07-10-2004, 12:53

I'm in the process of replacing a smoke alarm at a flat - the old one got broken - it's one of those attached to the mains, with a battery back up, which sounds when the battery back up goes. A tenant decided to silence it by breaking apart the casing and cracking the board inside, hence it no longer works properly.

I've got a new one to fit, and the instructions says I should run the powercables through a dry rising box... with the old one there was a kind of plastic box attached to the ceiling which the cables came through and the smoke alarm was attached to that. Is that the box? - if so where can I get another one? the screw holes are in the wrong place to attach the new one to it..

Does any of that make sense?

Thanks in advance

Shaun · 07-10-2004, 13:02

I'm sure someone with an answer will come along soon MLM but I hope you gave that tennant a pasting for distroying that smoke alarm. Some people don't know when they are well off.

Nemesis · 07-10-2004, 13:27

Never done this, so sorry ...

07-10-2004, 14:00

well a dry riser box is for access to water by the fire brigade, on each floor of a tall building, unlikely to be in a 'domestic' building.

It sounds like what you need is more of a junction box, you could try having a look in the electrical fixings in B&Q ?

**Chris** · 07-10-2004, 14:17

Quote:

Originally Posted by dellwear

I'm sure someone with an answer will come along soon MLM but I hope you gave that tennant a pasting for distroying that smoke alarm. Some people don't know when they are well off.

As a journo, I once attended an inquest into the deaths of two kids in a housefire (one teenager, one much younger - sevenish, IIRC). Among the things the fire brigade discovered during their investigations was a smoke alarm minus its battery. When quizzed about this, the father admitted he removed the battery because the alarm used to go off when his wife was cooking chips and it used to annoy him.

Great. I hope he can still watch his TV in peace.

Dave Stones · 07-10-2004, 14:19

it is against the rules in our contract to even touch the smoke alarms in my house... we get kicked out

anyway, the box. i think it sounds more like a standard back box or junction box, similar that get used in light switches/lighting circuits. these are available for under a fiver from b and q or homebase.... there are only two sizes as well, so measure up and see

SMHarman · 07-10-2004, 14:25

A dry riser is a vertical plastic conduit to pass the cables through, rather than punching a hole in the ceiling I guess. This could be to ensure the plasterboards fireproofing integrity remains, personally I think installation without is not likely to cause any problems.

Mr_love_monkey · 07-10-2004, 14:49

No, it's not an electrical junction box, it's just a roundish box the width of the smoke alarm...
I'm wondering if maybe it came with the old one, and I should just remove it, push the cable back into the ceiling space (where I assume there would already be a dry riser around it from what SmHarman says) - then attach the smoke alarm directly to the ceiling rather than to this box.

It could just be a case that I got confused as I didn't know what a dry riser was , and assumed it was this extra bit....

Electrics I can do easily... plastic boxes.. no

As for giving the tenant a pasting, or telling off or whatever... he's the one that I've mentioned in other threads, who has left after not paying rent for 6 months, run up large bills on charge cards that are registered at the flat - and helpfully removed all the light fittings....

zoombini · 07-10-2004, 15:58

I have partialy designed many smoke detectors, even the type that you mention & there has never been any requirment that they "must" fit to an additional box (although lots do) for any other purpose than to facilitate the fitting & maintenence, replacement etc by having the cables terminated with a terminal block & screwing into them etc.

If you can easily fit it by screwing it direct to the celing, with the wires passed through then it will be of no detrement.

Mr_love_monkey · 07-10-2004, 16:58

Quote:

Originally Posted by zoombini

I have partialy designed many smoke detectors, even the type that you mention & there has never been any requirment that they "must" fit to an additional box (although lots do) for any other purpose than to facilitate the fitting & maintenence, replacement etc by having the cables terminated with a terminal block & screwing into them etc.

If you can easily fit it by screwing it direct to the celing, with the wires passed through then it will be of no detrement.

Where could I get an additional box that you talk of? - the current set up is that the wires are in there with a terminal block, it would be nice if I could leave it like that?

SMHarman · 07-10-2004, 17:44

Quote:

Originally Posted by Mr_love_monkey

Where could I get an additional box that you talk of? - the current set up is that the wires are in there with a terminal block, it would be nice if I could leave it like that?

Sounds like you need to find the manufacturer of the original smoke alarm and replace it like for like, not with the new one you have purchased.

Mr_love_monkey · 07-10-2004, 17:46

Quote:

Originally Posted by SMHarman

Sounds like you need to find the manufacturer of the original smoke alarm and replace it like for like, not with the new one you have purchased.

That would be the best solution, but not one that is viable, since I don't have the time to do that.
I'll just take off the box and stick the new one straight on the ceiling

yesman · 07-10-2004, 19:32

Have a look here then scroll down to find the mounting plate which houses the connections, the connections must be made within this box and not pushed through the hole in the ceiling.

Hope that helps.

Edit: Did you mean dry lining box, it can be done using one of these instead of a surface pattress

zoombini · 07-10-2004, 21:16

Unfortunately I have no idea.
CEF, Newey & Eyre etc - eletctrical distributors?

OUr detectors usually have custom designed mounting plates/sockets that allow the detector to be twist fitted.
They are screwed directly into the celing using plasterboard type fitting AFAIKR. The cables are fed via a central hole, then onto the terminals in them.

In the situation of a domestic detector, the cable is usually the thinner 4 core type & can easly fit into the space where the battery used to be (removed & a psu PCB fitted instead).

Will it fit on the previous box but with some new holes made in it perhaps? They are not all the same diameter.