Electronic Alarms and Home Security Devices - Alarm Pre-Wiring Question

I want to pre-wire for an alarm installation. Should I be using 18-2 wire for magnetic switches and 18-4 for motion sensors, glass sensors and 4-wire smoke detectors>

Does the wire need to be twisted pair? Shielded? If not, is there any difference between thermostat wire and alarm wire? Both seem to be 18AWG and come with various numbers of conductors in a jacket.

Thanks,
David

Unless your wire runs are very long (500 ft +), 22ga is more than heavy enough. If you have access to the 18ga, go ahead and use it.

Shielded wire isn't generally needed, except for unusual hardware and environments for a normal alarm installation. The thermostat wire will likely serve you perfectly well. I've seen perfectly functional systems installed on old style telecom wire.

I had thought bigger was better too... I found 18/2 solid to be very rigid, and probably overkill, when trying to do my wiring initially, especially when getting it tucked neatly under the covers of my contacts. I gave up on that and only use it now for my power and siren connections. The 22/2 stranded is much nicer to work with especially when trying to tuck EOLs into the contact cover.

I'm using 22/4 stranded on my keypads and glass breaks too without any problems (although they are pretty short runs as compared to my window contacts).

I'm playing with a patch panel type idea using cat5 to carry 4 zones in one cable to the upstairs where I will use a wall plate with 4 RJ11 connectors to patch the contacts for each room. For something like this where the runs are parallel for so long the twisting is ideal (which is why it's in the cat5 to begin with) so that the EMF on a pair doesn't get transfered as current into an adjoining pair. I could just see one room being tripped and the panel showing all four rooms tripping at the same time if it were just 8 conductors w/out the twists). If the cat5 won't cut it (24AWG) then I'll put some 22AWG into the conduit and leave the cat5 for phone and network connections.

I've serviced an installation originally done by the owners son, a Baby Bell worker.

It was all done with CAT-3 with the zones split out where he wanted them. So far the wiring has outlasted 1 battery and a couple of motions that were victims of a near-miss lightning strike.

For zone contacts, most manufactures specify 22ga as a minimum, but unless you are running thousands of feet, the 24-26 will work just fine.

I've serviced an installation originally done by the owners son, a Baby Bell worker.

It was all done with CAT-3 with the zones split out where he wanted them. So far the wiring has outlasted 1 battery and a couple of motions that were victims of a near-miss lightning strike.

For zone contacts, most manufactures specify 22ga as a minimum, but unless you are running thousands of feet, the 24-26 will work just fine.

i have a small cottage approximately 20x30, and all the walls are exposed right now.

i've pulled cat5 for the data / telco, and was wondering if i could use 4pair cat3 for the keypads / motion sensors?

the run will be minimal, perhaps 15' each.

i believe the motion sensor is just a 2 conductor, but was not sure about the keypad?

any help i'd appreciate it.
thanks.
--j

Motions are pretty much all 4-wire devices (2 for power, 2 for alarm contact). Keypads are all 3 or 4 wire devices (a few are 5+)

Again, the alarm makers will only warranty if you use 22ga or heavier, but if that's not a concern, the telco wire will work just fine.