Hardwired burglar alarm

[Ro]

I'm planning to lay the cables for a burglar alarm in my apartment at the moment, and probably fit one at a later date, because I've got all the skirting boards taken up at the moment.

What I would like to know is: Do I need a separate cable to the control panel for each sensor, or just each zone?

I will have a patio door/window with 3 openings, and wonder if I can wire all 3 magnetic contacts with one cable?

I presume the cable to the bellbox is the same standard 6 core cable at the sensors?

Thanks

Ro

[Lurch]

On Sun, 25 Apr 2004 10:21:42 +0100, in uk.d-i-y Ro strung together this:

You can run 1 wire per zone and 'daisy chain' the detectors but it is better practice to run a 6 core cable from each detector to the control panel.

You can if you want, just remember to put them in series when you connect them up.

Yes.

[Ed Sirett]

It is really up to you. Most cheap panels are about 8 zone units although more zones are probably not much more costly.

I would happily combine the patio door sensors all into one zone.

6 core cable will be sufficient for all the wiring although you can do 2 zones down an 8 core or 4 zones down a 12 cores if that helps.

As far as combining other sensors the issue is whether any sensor would need to be treatd differently for any reason whatsoever than any other sensor (eg. exit route, part sent, chime etc. etc.).

HTH

[Alan Campbell]

Basically, as the other guys have mentioned, its up to you. One usefull thing about having each sensor on its own zone is that you can tell which one has triggered the alarm. This can be very usefull if you get a false alarm. The down side is that you can end up with lots of zones and it could get a bit confusing.

I put reed switches on all of the external doors (downstairs) and pir's in all of the downstairs rooms, and 1 on the upstairs hallway. I 'full' set it when the house is empty (all sensors) and part set it at night (excludes upstairs hallway). One option, rather than lost of reed sensors on each window opening, is to have the whole room protected by pir.

If you use pirs then dont forget to seal the cable entry point. I didnt, and we were woken at 1am on Saturday because a spider had crawled into the pir.

Alan

[Andrew Gabriel]

It is also useful to distinguish a false alarm. If you have enough sensors, it is unlikely an intruder will trip only one, so multiple sensors triggering is a better indication of a real detection. However, they have to be separately identifiable to the panel for this to be useful -- the panel can't tell two different sensors triggering if they are connected on the same circuit.

Also, you can't (easily) use multiple sensors per circuit if your alarm supports dual end-of-line resisters and you want to use that feature. (This also enables you to combine tamper and trigger functions into just two cable cores.)

Reed switches on windows (and to some extend doors) are most useful to remind you that there's one open when you arm the system. I suspect they are not of much less use at detecting someone coming in through the window.

or drill the cable hole so the cable sheath is a tight fit.

[Peter In Knowsley]

Vibration detectors are mainly used on windows these days, but mostly in cases where pets are left inside and the room isn't afforded movement detection.

''' Peter

[Peter In Knowsley]

If you are planning at some stage to get your system monitored by a receiving centre, I would advise you run an extra cable to rooms that have most valuables - that's if its not too much trouble to do. (normally people do this after they realise alarms don't stop people from breaking in)

Police policy these days require more than one detector to activate in a certain time window - normally 30 to 60 minutes - before they will attend. You would need a control panel compliant to the latest specs for this.

Run a wire to your phone point too. It would be neater to do it now while you have the place in bits.

''' Peter