Burglar Alarm Blues

[the]

My burglar alarm has not been activated for at least nine years and it is unlikely I will want to use it in the future. It hasn't been touched, serviced, tested or examined in any way either. The only benefit it gives are two blue flashing lights on the bell box on the front of the house.

It seems to be a generic no-name type and was installed by a previous owner. The only information I have on it are a few photocopied sheets from which I gather that at current electricity prices it's costing over eighty quid a year just to sit there.

There is no declaration of any burglar alarm in my house insurance policy so is there any reason why I shouldn't just switch it off?

To switch it off, do I just have to remove the fuse from the mains connection and let it run down? I don't even know if the back-up batteries are still viable - would that make a difference?

Thanks! (Real name obscured because there's no good reason for telling Burglar Bill and his mates who I am and that I don't use my alarm)

[Andy Burns]

If there's any life left in the external bell-box battery, then the sounder will go off and annoy everyone ...

[newshound]

But probably not for long.

[Tim+]

No reason not to turn it off BUT, the control board will almost certainly have a dead back up battery and the external wall sounder will have a battery that probably *isn?t* dead so the damn thing will scream to high heaven until the sounder dies. It only has a few button cells but the darn things last ages.

If you can, open the sounder box and remove/detach the batteries or speaker. If you don?t have a service code, the sounder will go off as soon as you remove the cover. Ear protection is a good idea as these things are LOUD, especially when you?re at the top of a ladder. ;-)

Tim

[nothanks]

There will probably be two batteries, one in the control panel and one in the bell box. Switch off the mains to the control unit (enter the code if the alarm sounds), open the control box and remove the battery (enter the code if ...) and disconnect the wire to the bell box. If the bell box has an LED to show that it's powered then why not keep that powered with a small PSU - seeing it may deter a scrote.

BTW £80/year seems rather high - are you sure of your sums?

[alan_m]

My bell box has a large Nicad cell and maybe the same vintage as the OPs alarm

[williamwright]

One penny per hour? 45W? (I failed maths O level)

Bill

[the]

Ta. Good idea.

135mA claimed consumption by the control box. I presume that includes all the peripherals. 135mA x 240v x 24hrs x 365 days /1000 for kWh. 284kWh x current price of 28p/kWh = £79.52

What have I got wrong?

HH

[John Rumm]

Is that 135mA at mains voltage, or is that a DC input with a separate PSU?

[Andrew]

My Swish Autoglide curtain opener/closer is 20watts, so that would be about £52/year at current electric prices if I still used the control unit and motor.

Been used 'doors to manual' for years. You only need to pull/push one curtain and the other moves itself thanks to the drive belt.

My Smiths bulkhead PIR light (circa 1985) is probably the same so that is only energised from dark to midnight by being plugged in to an electro-mechanical time switch. Still costs about £13/yr but unlike chinesium tat it is now 37 years old and going strong.

[Mike Clarke]

135mA x 240V = 32 watts. If it's really using that amount of power I'd expect the casing of the panel to be noticeably warm.

[nothanks]

Nothing wrong with the sums if the current is correct (but 32W seems a little high and, of course, it's supposed to be nearer to 230V these days), I'd forgotten that the cost/kWh was so high :-(

[the]

Control Panel Current Consumption Standby 137mA Alarming 170mA

There's a mains connection via a fused spur plate so no DC input.

HH

[the]

..and you'd be right. Hold your hand above the ventilation grille and you can feel a gentle rising warmth. There are also convection streaks on the wallpaper behind the unit.

HH

[Robin]

<snip>

Did they finally change from 240V as the "real" target that remained in place within the harmonised EU range of 230V +10% / -6%?

[NY]

Whenever I glance at the mains meter plugged into one of my sockets, which measures voltage and frequency, and if anything is plugged in, current and power, it seems to read around 240-250 V. I'll have to measure the voltage with a multimeter since that is a *little* more likely to be reading true (though it's never been accurately calibrated).

[Martin Brown]

+1

Though any local burglar Bill will notice that your external blue light has stopped flashing.

BTW Are you sure it is really costing you £80/year? That seems like a very high load for a trickle charger.

Mine measures about 10W or £20 a year (and I use mine).

Household baseload is presently 80W after some additional tweaking spurred on by the new smart meter display. There are quite a few smart gadgets each using about 500mW and the internet modem and router 24/7.

[williamwright]

30W satellite boxes feel very warm if there isn't good ventilation.

Bill

[alan_m]

I had one of the early Humax HD Satellite boxes. After 30 minutes of operation the base of the unit was at a temperature that was almost too hot to touch without inflicting pain.

The intermittency of one of my friends latest Sky box was cured by just raising it up on two small pieces of wood to allow some more airflow beneath the box.

[Chris J Dixon]

The data from my OpenEnergyMonitor kit reports, since November

2020,

Min 228.4, Max 243.5, Mean 238.8

The 228 was a single 30 minute dip, and looks very much an outlier.

Chris