Replacing old fire alarm detectors

[sarahw]

I want to replace both a heat detector and smoke detector in my flat. The detectors are linkd to a central system for the building and all flats. I've managed to disable this for the change and having boughtnew ones from Screwfix, took the covers off the old ones to find the attached. The Screwfix ones come with no instructions, so I'm guessing that all detectors have a standard 4 connection wire fit. If so, how do I know what wires to connect to what with teh new unit?

 

[nozspark]

You mean you have disabled part of a panel alarm system which protects the whole building??????

You should not be doing this...

and anyway, you would need to get the same make sensors as the panel and be able to test the system and provide a fire alarm certificate for the alterations that you have made.

 

[Steve]

Only qualified people may alter this system. It protects the whole building and therefore everyone in it. PLEASE dont do anything else until you seek the help of the maintenance company for the building or an electrician who knows fire alarms.

 

[333rocky333]

How did you disable the system?

 

[sarahw]

I meant I disabled the detector region for my flat. I met tehguy who services it each year and he knew less abot it than I did and he was fine with me replacing the sensors. He said they're all standard for heat and smok and it was him who showed me how to disable my flat sensors in order to change them without setting the building alarm off.

Only prob is that the new ones don't have instrucitons. They've got 4 connections and two are spanned by a diode so I can work out what wres to coenct theseto from the existing ones, it's just the other 2 I'd like to work out insteadof jus doing it by trial and error

 

[1john]

pictures would be a start....

 

[333rocky333]

Theres no instructions as they are meant to be fitted by competent persons.

There are many variations and you jeapordise blowing the circuit board.
Not all units are compatible and some are different voltages.
As well as different types of smoke and different temperature heat.

You should get the part no off the units and order the same ones, then get this bloke to fit and test them on the existing bases.


The bloke should have known better, disabling part of a system could render him liable if an incident occured.

The panel will also show a problem whilst it is disabled.

The diode is there so the panel can detect the head is missing but still allow sensors and mainly call points further on to work unhindered.
This is sometimes in the + line but may be in the - line.
Therefore the in and out supply has to be correct.
The other two terminals are sometimes a solid link on the base, but not always so.

How did you propose to test them after anyway.

 

[flameport]

I meant I disabled the detector region for my flat. I met tehguy who services it each year and he knew less abot it than I did and he was fine with me replacing the sensors. He said they're all standard for heat and smok and it was him who showed me how to disable my flat sensors in order to change them without setting the building alarm off

This is all very bad news.
The person servicing the system has given you completely wrong advice regarding detectors being 'all the same'. They are not.
They should not have left the system in an incomplete state, as the whole point of it being serviced/checked is to ensure the whole system operates correctly.
Fire panels in shared buildings should NOT be set up so that users can disable zones or any other features. The danger is that someone disables a section of the system for some reason, later there is a fire, and then the system won't work. People could die.

I suggest you return your new sensors for a refund, and contact the management of the building so they can arrange for a decent and competent alarm company to repair any damage, replace your sensors and make sure the system is actually working as intended.

 

[Taylortwocities]

Darwin was right...

 

[sarahw]

Yikes... Glad I learnt how to add a socket spur and add recessed lighting to my bathroom and not ask here or else I might have got as many lectures on electrical work

FOund this really useful:
http://www.screwfix.com/prods/55127/Security/Alarm...

In the end, the 2 black wires went together and just had to work out which of th red was the positive and which was the negative. All fixed now and they work well... it's actually dead simple and the new ones look nice and shiney and no doubt far safer than the ageing ones that were there

Thanks,
S

 

[Taylortwocities]

Yikes... Glad I learnt how to add a socket spur and add recessed lighting to my bathroom .........had to work out which of th red was the positive and which was the negative.

Positive? negative? I don't think so....

In my house we have live and neutral

 

[bernardgreen]

I sincerely hope this is a wind up.

Because if it is a true story and there is a fire in the building then sarahw could find herself liable to paying damages or facing court actions.

If there was a loss of life due to a mal-function of the fire alarm the court action faced by sarahw could be a charge of manslaughter.

Even if there was was a fire with no serious loss of property and no injury a post event examination of the fire alarm system will be made and the un-authorised alterations made by sarahw will be found. These altereations could still be the basis of a court action. This could be from the building's owner, the building's insurer or other residents in the building or their insurers.