Isolating the Supply problem

[dv6]

Hiya everyone. Im a Level 3 2330 student and in the next year i want to pass Level 3 and 2391. Ive bought a multitester and want to practise on the electrics in my flat, run the various tests etc.

My problem - somebody in the past has wired an alarm system into the flat. When i isolate the whole supply the alarm goes off !
Now i need to isolate the whole supply at first because i have to identify which circuits which and im not doing that on a partly isolated CU.

How can i isolate the CU without this bleeping alarm going off ?

The alarm has been wired into a dedicated shower radial. I believe the alarm should be on its own radial. I suppose i could leave this circuit live as im going to be fairly positive that this circuit is the shower. Its an 8.5kw shower so likely to be the largest mcb in the CU. Not sure what to do to stay safe. Any ideas ?


cheers

 

[Space cat]

The alarm has been wired into a dedicated shower radial.

I hope there's a fuse somewhere between the shower supply cable and the alarm! Even so, it's still wrong and you're right --

I believe the alarm should be on its own radial

That would be the best way. You could also spur it off a ring with an unswitched FCU. Meanwhile --

When i isolate the whole supply the alarm goes off !

That's wrong too. The alarm should NOT go off every time there's a power cut. Either your alarm is faulty or your backup battery is flat.

 

[Steve3948]

Most people fail to replace the back-up battery every 3 years like you should.
Also many don't even have a back-up battery, so the SAB Module triggers the external bell whenever the power fails.

 

[dv6]

Thanks for the replies. Thats fantastic. I knew something wasnt right. Is it possible for me to fit a new battery to the alarm system or do we have to get an alarm engineer out to do it ?

 

[Steve3948]

Open the panel door, note the battery serial number and obtain a new one from your local battery centre, then swap new for old.

 

[Space cat]

You certainly don't need an alarm engineer to change a battery. Who needs alarm engineers when you've got DIYnot.

Be prepared for the tamper alarm to go off when you open the box. With any luck, since the alarm won't be armed, it'll only be a small, internal beeper. If there is a battery in there then this --

note the battery serial number and obtain a new one from your local battery centre, then swap new for old.

from Steve3948 is sound advice. If you can't see any battery - and they're difficult to miss - you'll need the manual. Maybe it was never designed to take a battery or, if it was, nobody ever fitted one. Somebody might even have removed a duff battery to fix a fault and never replaced it.

If there is no provision for a backup battery you should disable the self activating bell to prevent nuisance alarms.

 

[dv6]

Ok cheers. Ill give those a try

 

[securespark]

If it's an ADE panel, the compact (two-piece cover) will accept a maximum 1.2Ah, the standard sized pnels (one piece cover) up to 7.0Ah.