Well chaps, I bit the bullet and bought a s\h Euro 44+ panel, which so far has worked out OK, just programming it up at the moment.

 

I know this will have you all rolling your eyes, but hey, £20 and an afternoon of swapping the wiring is not to be sneezed at.

aand I'm back!

 

OK, Looks like the original system was working mostly via blind luck. From what I can tell, there are no terminating capacitors fitted anywhere (or I haven't found any yet), and the system is detecting only 4 of the 9 id zones. For added fun, looks like several of the runs aren't in shielded cable either. :| I've tried swapping a biscuit from one PIR to another, and the zone number changed OK, so the fault appears to be in the wiring rather than the biscuits.

 

There's also a rather strange arrangement where some of the ID wiring follows the 12v power in the same cable, then a second cable at the panel which had ID+ and ID- only, doesn't carry power, but was carrying signalling to a seperate dialler.

 

Anything to lose by adding a capacitor to each PIR? All the PIRs appear to have a single cable run to them, so I guess that would be considered the end of a run.

 

I did also wonder about boosting the ID line voltage a touch. it's 6.51 on midpoint at the panel with everything in-place, but I'll see what the voltages are like at the PIRs.

 

(btw, you are now all allowed to point and mock the DIYer. )

Caps are not normally fitted mind

I was looking at the suggestions here http://www.castle-caretech.com/wh/manuals/misc-id-plus.pdf and in the panel manual, which suggested a 0.01 uf capacitor at the end of each cable run. As each detector has a single run to it, seems reasonable.

 

I'll test each biscuit too, in case there is one or more faulty ones causing a problem - all this started with a mains power problem after all.

One question, what *type* of capacitor is used for ID termination? I can find hte value in everyone's docs, but nothing about the type.

 

Is the small ceramic "bead" type suitable?

At low values it will be irrelevant AFAIK. It was a bead one comes with brand new texe ID adaptor kit AFAIK.

OK, one trip to maplin later,

 

these

http://www.maplin.co.uk/p/resin-dipped-ceramic-001uf-capacitor-ra44x

 

these

http://www.maplin.co.uk/p/mylar-film-001uf-capacitor-ww18u

 

and these

http://www.maplin.co.uk/p/decoupling-ceramic-disc-001uf-capacitor-bx00a which will be tried first, thanks to the "decoupling" description.

 

We'll see if any of those make a difference.

I think its highly unlikely to be caps (type, or lack of) on a short run domestic.

 

I would suggest testing all the cables with every device disconnected for shorts or high resistance

If each detector is cabled back to a central point now would ne a good time to ditch the id and go deol

And if there is only a 4 core to the central point, just swap the junction box for a node / LIM / RIO whatever