9651 - isolate zone to lengthen cable

[TheLiquidator]

Hi - complete Newb hear.

Have a scantronic 9651 alarm. Have had a new floor put down in the entrance hallway (wood to replace carpets) but unfortunately forgot there was an alarm cable under the carpet going to the front door sensor.

I need to cut into the cable to lengthen it (the closest I've been able to find is 4 core phone cable) but don't want to drive the neighbours mad as I'm sure it will set the alarm off as a tamper. Can anyone advise me how to do this please, or is it an engineers job?

Much obliged.

 

[Europlex]

Not a good idea to use phone cable, the cores are single stranded and break very easily. That's why alarm companies, these days, use stranded.

Years ago, alarms installed, mostly by the big nationals, used to be the single stranded stuff, an absolute pain in the a**, always breaking.

Try Screwfix, they sell alarm cable.

 

[EightyTwo]

First things first - DON'T CUT THE WIRE! Depending on what it's going to, it may have a 12V supply and/or data in it and by cutting it, you could short something out and cause all manner of problems - a tamper would be the least of your worries!

If the cable is going to the keypad, it might be best to get the engineer. If it goes to the front door contact then it should be relatively straightforward to extend it. If possible, run your new cable from one end to the join (or better still, replace the whole cable). This will mean that you only have one joint. Joints are inherently unreliable, especially if placed under flooring. The best way to do it is to strip, twist and trim each individual conductor, solder the joint and insulate with heatshrink or tape.

Open the panel (beware of mains in the top left corner) and enter your code at the keypad to silence the tamper. Find the cable and disconnect it from the main board - you may want to put the battery on the top of the panel (without disconnecting it) to keep it out of the way.

Then do your cable work, reconnect it in the panel, put the lid back on and put your code in reset the alarm.

Remember that your installer (if it's under a maintenance contract) may not be keen on you doing your own modifications to the system.

 

[sparkymarka]

lets just hope its not on engineer reset for tamper....

 

[Europlex]

lets just hope its not on engineer reset for tamper....

I hear what you say, it's just that I have never come up against that.

 

[EightyTwo]

I never understood firms who did that - the last thing I want is to get called out to poxy tampers, line faults and mains fails that the user can't reset themselves!

 

[sparkymarka]

The other issue is the 9651 comes with the panel lid tamper as engineer reset unless the engineer has changed it to user reset.

 

[TheLiquidator]

Okay thanks for the input folks - boy am I regretting changing that carpet for a hard floor!

Anyway I've ordered some alarm cable which should be with me in a couple of days.

On the tamper front, I have a PIR on the landing over the bathroom door which has had a tendency to go "rogue" now and then. Whether it was an atmosphere thing I don't know but even when the alarm was not set, if it detected movement it would go off and was reported as a tamper on the keypad. Typing in the user code (twice) turned it off and reset it so am I right to assume I have user reset? As an aside the only thing I was able to do was to cover the PIR with a black bin bag for a day or so and then it was okay again (causing me to question whether steam from the bathroom affected it). Anyway I digress.

The alarm was professionally fitted a few years back. Until I pulled up the carpet it's fair to say the installer left no wires visible at all.The cable in question emanates from the main box, which is in a cupboard on the landing at the rear of the house. It runs in the bedroom floor void to the front of the main part of the house where it drops down through the partition wall and comes out at floor level in the hallway. From that point the hallway has breeze block walls (and gas box and electric consumer unit) which is I presume why this wire runs under the carpet.

I very much take the point about cutting the cable. However I didn't realise it was relevant at the time, but when it emerges from the partition wall there is already a join in the cable. From what I have said about the upstairs PIR should I be able to disconnect the cable there, key in the user code once to switch it off, replace the cable then key in my user code again to reset? That seems logical to me as there must be some way to say remove the PIRs from the wall if I need to replace the wallpaper but I know logic won't always apply.

Sorry this is convoluted and I hope it makes sense, and thanks for your help

 

[EightyTwo]

You still didn't say where the cable you want to extend ends up... Contact? Keypad? Hall PIR?

You should be able to extend it from the existing joint. Just remember what I said about short circuits.

A good trick to help you remember the colours at the other end it to open up the contact (say) and cut each wire individually leaving about 1/4" of insulation on the bit connected to the contact. You can then use the old cable to pull the new cable through any holes/ducting/voids. When you're done, you can prepare the end (use the rip cord to strip the outer), get the contact and reconnect each colour, one at a time. Finally, do the joint.

As for your landing PIR, check that all the connections are tight and give all the wires, and any resistors, a little tug to make sure that they're in the connectors. A PIR shouldn't generate a tamper when you walk in front of it! Whilst you've got the lid off, you could also check the tamper switch spring/lever. My thought would be that the 4k7 alarm resistor (if fitted) is loose at one end. This is the one across the alarm terminals (yellow, violet, red).

 

[TheLiquidator]

Thanks for the response. I'll take a look at the PIR next time it plays up, if it does. The info is very useful in any event as I'm bound to want to take down the one in the lounge at some point when I want to re-decorate.

To answer your question: the wire is going to the front door contact so I'll disconnect the wires at the join (taping over the ends one by one as I undo them) and then remove the contact from the door-frame. Whilst the contact is simply screwed to the door-frame, I suspect the cable has been fed into the frame because I can't actually see it, so I'll work back from there to the join.

Once again, thanks for the assistance which has given me the confidence to tackle this.

 

[TheLiquidator]

Back again.....

I have just started the job. Undid the first of the joined wires and, as expected, it set the alarm off. I keyed in my user code once and it was silenced ... for about 10 seconds! I then had to type in my user code twice more and got.... another 10 seconds silence!

Is there anything I can do to shut the bloody thing up for the 20 minutes or so I need to do the job, or is it time to call in the engineer do you think? I need to fix it by Saturday so there's no rush then!

Thanks in advance

 

[EightyTwo]

Take the contact out and look at what is connected to what. Then split the joint and replicate the contact wiring on the 'live' end of the joint.

This may take a minute ot two but it will give you time to run your new length of cable.

You'll either see just two wires going onto the contact with two resistors or two wires to the contact's silver screws and two wires twisted together on one of the brass screws.

If you've got resistors, connect the 2k2 (red,red,red,gold) across the two colours that were on the contact. You don't need to worry about the other resistor, yet. If you have four wires, just twist the two that were twisted in the contact. This should clear the tamper fault whilst you get on with the rest of the cabling.

Have fun!

 

[TheLiquidator]

Thanks for the reply.

The installer had actually excelled himself as he managed to take the cable inside the UPVC door-frame and behind the contact there is a small hole where 2 wires come out and I can see that there are more wires inside the frame although I can't see what they are connected to, if anything. So, whilst it's not ideal, it looks like it's going to need a join, as I suspect there's no way I'm going to be able to replace it. I can easily hide it as I'm going to run a section of the cable under the door threshold, which I can then seal in.

I have managed to get hold of the installer and he has talked me through disabling the contact circuit at the keypad, so I can now undo the cable which, by implication, will enable me to do the job, so that's my task for the weekend. I'll then ring him up when it's done and he'll talk me through re-enabling it again, so it's fingers crossed.

Thanks for your help