Alarm Problem (Possibly OT),

[Charles Middleton]

(If this is OT please feel free to direct me to the required NG - thanks).

I turned my mains power off yesterday at my consumer unit and was suprised to hear my burglar alarm ringing from the outside. Its never done this before. I though that if the mains went off (powercut etc) then the battery in the system would power the alarm. When I restored the power the alarm stopped sounding.

The battery cant be flat I presume as otherwise the alarm wouldnt sound at all with the mains off. I took the battery out of the alarm control box thingy and tested it with a multimeter. It showed approx.

12 volts so it cant be flat.

Any ideas?

CM.

[MrCheerful]

The alarm is taking the power out as being a problem and is sounding, any good alarm also has a separate battery for the alarm sounder itself, so the battery in the alarm unit indoors is beside the point!

Look at the literature for the alarm, you will probably find that the power off alarm is intentional, I had to disconnect mine when I installed the system as I considered it might be a nuisance.

MrCheerful

[Lurch]

On 1 Mar 2004 05:04:43 -0800, in uk.d-i-y [e-mail] (Charles Middleton) strung together this:

But it is though. You need a new battery. The external sounder has its own batteries so will continue sounding even with no mains or battery at the control panel. ..

SJW A.C.S. Ltd.

[JhnWil875]

Not all alarm systems have a battery in the bell box, some are powered by the accumalator in the alarm panel housing itself.

John.

[Lurch]

On 01 Mar 2004 14:17:05 GMT, in uk.d-i-y [e-mail] (JhnWil875) strung together this:

The what in the panel? Some systems will be setup to draw power for the external sounder from either the control panel or the battery in the bell box itself. Maybe I should have said *most* likely problem is the battery in the control panel. If it never did it before then it's not a control panel feature, it's a knackered battery. Your response may be spot on for some one elses panel, but not this one. ..

SJW A.C.S. Ltd.

[Dave Liquorice]

Seems to indicate that the battery in the panel is knackered. Any decent system will have a battery in the sounder as well as in the panel. The sounder is "held off" by volts from the panel. If those volts disappear (cable cut, duff panel battery during power outage WHY) then the sounder will decide something is amiss and make it's displeasure known, running from it's own battery.

You need to see what it is under load, a 6W side light from a car will draw about 1/2 an amp and do as a suitable load. Or, if your neightbours don't mind the noise, measure the voltage with the battery installed in the panel and the mains to the panel switched off.

TBH 12v off load for a fully charged SLA seems on the low side to me, I'd expect over 13v.

[Sparks]

I was going to suggest a flat battery in the panel, however.....

It still could be knackered - try turning the mains off again, and look to see if the panels lights go off It could also be a fuse for the battery has popped, so the battery is not getting charged or used in the event of a power cut If you take out the battery, then measure the leads that connected to the battery, what do you get?

What make/model is the panel?

Sparks...

[nick smith]

Surely this IS the symptom of a dud panel battery, and the Exterior bell box battery powers the external sounder as it thinks its supply cable has been cut !

Nick

[Lurch]

That too. It could be either. If the battery fuse has blown then the SAB thinks the cable has been cut because it's receiving no power. ..

SJW A.C.S. Ltd.

[Charles Middleton]

Hi, I meant to have a look at this this weekend but got distracted on other jobs. Ill have a look when I'm back at the house the following weekend.

Cheers,

CM.