Electronic Alarms and Home Security Devices - Alarm Wire

When I Built my house I ran 3 runs of Cat 5 wire from each room to the basement and a few extra runs of cat 5 from the attic to the basement

My question is I am installing an Ademco 20P can I use the cat 5 wire which is 24 gauge for the window contacts and or the smoke detectors?

Jacob

24gage is to small.

I would use 18-20 gage.

The common size used for residential alarm systems, and commercial security alarms, is 22 guage, except for siren and power transformer, which is typically 18 guage. You could get by with the 24 guage on your contacts and other burg devices, and really on your fire, as long as it's CM wire. It should say on the jacket cm2 or cm3. It could have an R or P after cm, and that's fine. CL is not allowed for fire alarm systems. It's all a matter of voltage drop, and none of the devices use enough current for that to be a problem in a typical house.

Integrator is correct in that the smaller gauge wire _will_ work. However, the specs for nearly _all_ security alarm systems do specify 22 gauge as the minimum wire gauge. Just realize that the smaller wire is much more fragile.

Also, many of the connectors and devices sometimes have trouble getting a proper connection with the smaller wire (the screw terminals sometimes just don't close tightly enough, so you have to double up the wire).

When you say double up on the wire are you refering to using 1 pair as if it was 1 wire?



Thank you all for you Input

No, you strip the end going into the connector longer than normal and fold it double so that there is enough wire bulk in the connection for the terminal to clamp down on. Otherwise, the wire terminals in many alarm devices simply won't grip this smaller wire properly (i.e. random false trips and troubles).

Thank you again
I'm sure I will have more questions as I start hooking up the system

Jacob

I found this in a VISTA-20P installation guide:


Size__50mA__100mA__300mA__500mA__600mA
#22___900'___450'___150'___90'____75'
#20___1400'__700'___240'___140'___120'
#18___1500'__1100'__350'___220'___170'
#16___1500'__1500'__550'___350'___270'


and this in a VISTA-20 installation guide:


Size__50mA__100mA__300mA__500mA__600mA
#22___500'___250'___80'____50'____42'
#20___750'___380'___130'___80'____67'
#18___1300'__650'___200'___130'___115'
#16___1500'__1000'__330'___200'___170'


For the transformer:
0 - 50 feet #20
50 - 100 feet #18
100 - 250 feet #16

Not sure why the difference between the two manuals. Both suggest nothing longer that 1,500 feet for auxillary devices and 250 feet for the transformer.

The V20p has a larger power supply and has the power reserve to overcome a larger voltage drop.