In message , AlanC writes
It's a battery.
Intruder alarms should only sound for a certain period of time, IIRC it's 30 seconds for car alarms and 20 minutes for a building. It can be considered a nuisance under environmental protection laws if it sounds for longer and it's a nasty fine if they decide to prosecute.
In message , Stuart Noble wrote
Sod's law will now operate.
Make sure that your neighbour has the alarm instructions to hand. Make sure that he understands them before opening up the control panel. He may need to re-program the box. My alarm manual was a very poor translation into English from a very poor set of instructions in Chinese :(
There will be an anti tamper switch (on a spring) in the control box that will trigger the alarm when the cover of the control box is removed. It may be sensible to replace the battery (without removing the mains) before the wires to the bell box are repaired - or else panic number two will set in.
But there should be a (separate) timer on the antitamper circuit in the bell box.
Owain
The offence is the alarm sounding for more than 20 mins, so it wouldn't matter when the panel was fitted. You are not required to retrofit, but if your old bell goes off for more than 20 mins you commit the offence.
If the old bell box doesn't have a strobe it would be well worth replacing it with one that does - (a) it is easier to locate which house has the activated alarm; (b) the strobe can continue after the time limit, providing a warning to the returning occupant that someone may have been (or may still be) inside the house.
Owain
In article , Stuart Noble writes
In modern systems both panel and bell boxes have timeouts to avoid this sort of problem. To avoid a reoccurrence, your neighbour could replace the bell box with a modern one or just swap over the electronics, sounder and strobe. This low cost one would do the job:
Screwdriver, ladder and ear plugs could have shortened the 2 hours of night time fun.
What will have happened is that self actuating bell has activated due to the control panel's battery failing. The battery in the control panel should be designed to keep the system active in a standby condition (or set) for upto 20 hours. After this time, it will no longer provide the hold-off supply to the bell box, which will activate itself. This bell should have a 20-minute timer on it after which it should cut out.
From the sounds of it, he needs a new battery, the system will need servicing as it's probably not been done, and he'll need a new bell box that is compliant with current regulations.
Some do, but it's a battery test function which would have saved you from this one. This switches the alarm to run from battery for a period of time. If it hits a low battery state during that, it generates a battery failure warning, which is subtley different from a low battery warning (which isn't necessarily a faulty battery). The default programming for mine is to run the battery test once a day, but you can change this, and also make it do it on demand.
I'm not so sure that external audible alarms are any use anyway since everyone seems to ignore them.
I'm actually thinking of installing an internal (very loud) alarm on the basis that when I worked in a nuclear facility we had an internal alarm to warn us if the radiation levels exceeded a certain level. The alarm was tested every week and believe me, everyone left the building very quickly because the noise was horrific. So I would expect any burglar would do the same.
The trouble with a strobe is that if it's flashing away for hours on end there's a very strong likelihood that there's nobody at home, and that it's safe to break in.
A good alarm should reactivate after a time-out if any new sensors are activated (eg if the door sensor has been activated then the alarm will reset with it disabled but still resound if a PIR is activated) but burglars know that if they trip an alarm often enough it will usually be turned off either manually or automatically and the property left unalarmed. That's why commercial premises alarms are usually engineer-only resettable.
Regardless of whether there's a strobe or not, if no-one responds to the alarm then chummy will get the message that it can be ignored. Having a strobe might make it a bit more obvious to him, I agree, but it shouldn't be a weakness in security. On the other hand, a warning before you go into a house that might have a burglar still inside is a very valuable increase in personal security.
Owain
That's why my strobe is linked to the bell, and stops when the bell stops.
That could be achieved by a LED in a corner of a window, rather than a bright light flashing away on a box on the side of the building visible from a long distance.
A few months ago we had a power cut. One of the houses nearby was unoccupied but fully furnished and the strobe on their alarm flashed for the following six weeks...
That's quite commonly done. Even when the panel does have a separate strobe output, many installers prefer to connect the stobe to the siren output instead for this reason.
All very well - but most alarms are false alarms IMHO.
I'm glad the posters here maintain their systems properly but where I live - during a power cut there are always several alarms going off.
M.
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