sean5302

Why's that, please? If there's 6 and 5 seem OK, why would 1 fail? The temptation is to try pulling a bit out of the wall, cutting a few inches off and testing again, but the break could be anywhere is a cable 40 feet long, so it's nonsense really. It just seems so strange to me that a single core would fail in a sheaf of 6.

It just seems odd that a cable containing 6 separate wires can suddenly lose continuity in 1 or 2 of them, but that is what has happened. I'd have thought a mouse or rat would chew the whole cable but, despite ensuring that the connections are sound at the control box and at the PIR, that's what's happened. It doesn't seem worth trying to replace that zone wiring. A neighbour says the wiring is inside the cavity walls and it's beam and block flooring at ground level, so everything's buried really.

I'm not convinced. There are 6 wires in the cable going to the PIR. At least 4 of them are working fine. My next job today will be to solder the ends of the 2 wires for common and NC, at each end. These are very low voltage feeds, therefore resistance will play a big part. If it works, great. If it doesn't, I now have a 5-zone alarm rather than a 6-zone one. Cutting holes in the floor of a newish house isn't an option. There are no "boards", it's floored with chipboard so exposing small sections of cable isn't going to tell me anything. Thanks for your help, guys.

I'm still a bit perplexed. The PIR cable has 6 wires in it. 2 power wires are OK ie 0 and 12V. The PIR lights up when I walk in front of it. 2 Tamper wires are OK. The tamper circuit activates on removing the PIR cover. There is a fault with either common or NC so the PIR is effectively open circuit. How can that be? Is that an unusual fault, please? I suppose I could check the connections again for the common and NC both at the PIR and the control box, but it does seem strange. What do folks think?

I now have most of my answer and, unfortunately, it's not what I wanted to learn. Looping zone 4 out at the PIR doesn't cure the fault. Looping zone 4 out at the control panel does cure the fault. This suggests a wiring fault. I believe the wires are hidden behind the coving at wall/ceiling height. I cannot see anything other than a thick cable coming out of the control box and disappearing into the coving, which then turns through 3-off 90 degree bends before going 30 feet down the hall towards the dining room. Is it likely that this wiring will be clipped in place behind the coving? I don't know which would have been fixed first, probably when the house was being built. I suppose i could just ignore it and carry on, since the alarm works as intended except for in the dining room. I have once heard "rustling" as if from a mouse, but can't think how one would get inside the coving. I'll have a look upstairs but the only area with a few small places of access would be in the hot water cylinder cupboard upstairs. How do installers usually fit alarm wiring in new houses? I'd hope that I could tie a string to the cable behind the PIR in the dining room and pull the damaged cable out towards the control box, using the string to then thread a new cable in. More likely, I'll just ignore it. There is power to the PIR and also the tamper circuit works, so it's something with the 2 wires for NC and common. Any help gratefully received, please.

I'm not prepared to pay £200 to get someone out to it. By "loop it out" are you saying just fit a piece of wire across the terminals previously occupied by the PIR? Do I have to do that in Engineer Mode? If I just open the cover, remove the PIR wires from zone 4, bridge the terminals with wire, refit the cover and reset the alarm, would all be OK until I replace the PIR?

Hi folks. I have a 14 year old Scantronic 9448ES alarm with newish Pyronix Belle box and 14 year old Pyronix hard-wired PIR detectors. There is a fault on zone 4, the PIR in the dining room. As soon as I try to set the alarm I get the beep beep at the keypad but zone 4 light stays lit continuously, followed by full alarm sounding after 20 seconds. Therefore zone 4 is in full alarm triggering mode. It won't go into engineer mode. I key 0 followed by 7890 and all LEDs should then flash, but they don't. Also, it won't walk test. No obvious response from anything when I key the relevant code in. You guys said I should loop out zone 4.(I asked the question before). Is that remove the 2 wires from zone 4 in the control panel and then bridge the terminals (ie closed) or do I leave theterminals unconnected to anything (ie open)? Nothing looks wrong with the PIR, which lights up when walked in front of, but I know neighbours who have had faults with their PIRs and had to get them changed. There's no spiders, dirt or obvious contamination. If I part set the alarm, omitting zone 4, all works fine. Any help greatly appreciated, thanks.