Burglar alarm

[fatty]

Why does my burglar alarm ring when I pull the fuse out from my upstairs lighting circuit? How can I stop it doing it?

 

[EddieCurrent]

Hello,
It stops an intruder from entering your home , and simply turning the alarm off. (so that he can grab your valuables without the alarm bothering him ). Think of it as a tamper switch maybe.

 

[fatty]

Hi. Thanks for that. I want to change the light switches though and don't fancy doing it on a live circuit. How can I switch off the alarm?

If it is connected to the lighting circuit for its power, how does it still ring when the fuse is pulled? Is there a battery in it somewhere or is it connected to a secondary circuit of some sort?

Cheers.

 

[jj4091]

Yes it does seem to be supplied from the lighting circuit, there will be a battery in the main panel of the alarm & also one in the bell box

 

[fatty]

So is this a sensible approach:
1) remove fuse from lighting circuit
2) open burglar alarm box (test to make sure it's not live) disconnect battery.
3) repeat (2) for bell box

Thanks.

 

[EddieCurrent]

Hello,
Is you system quite old ?
I think that maybe the battery inside the panel may be failing, as they should keep the system running for a good few hours, and your battery could be flat.
There is also a chance that an internal fuse between the supply and battery has blown and this is stopping the battery from charging.

Is the whole system ringing, or just the panel ?
I am not an alarm fitter but am interested to know if the whole system is activating, or just the panel buzzing etc.

Cheers.

 

[Adam_151]

Sounds like you need to change the battery in the main panel

(what would you do in a powercut )

 

[fatty]

Thanks for the replies guys. When I remove the lighting circuit fuse the alarm rings exactly as it would in the event of an unwanted intruder (a full on, ear bashing, baby waking event).

I'll check the fuse and battery later. Why is it connected to the lighting circuit though and not on its own?

If the battery were dead or not charging properly, how could the alarm ring when the fuse is removed?

 

[bernardgreen]

If the battery were dead or not charging properly, how could the alarm ring when the fuse is removed?

TWO batteries. One in the control panel to power sensors during power cuts and one up in the Bell box that powers the siren any time there is NO voltage coming up from the control panel. So a lack of mains and a dead battery in the control panel means the bell box has no voltage applied ( called the "hold off" voltage ) so the bell box activates on its own battery.

This is so that the burglar who cut the wire to the bell box sets of the alarm by doing so.

The battery in the bell box is ( should be ) a far better quality battery than the cheap easy to replace one in the control panel.

Get a new battery for the control panel. ( Maplins ) give it 24 hours to fully charge and then try turning of the mains. If the alarm sounds then the charger and/or battery fuse in the control panel is blown.

Bernard
Sharnbrook