Honeywell Vista 20P Shopping List

[tangent]

Forgive my ignorance, but when you say "doubled up" are you saying using 22-4 wire and then when using a window/door sensor, such as the 944T, that you would hook TWO of the wires up to one terminal of the 944T and the other TWO wires up to the other terminal of the 944T and then of course hooking up the same pairs together at the Vista 20P panel?

No.

What I'm saying is plenty of trunk slamming alarm installers don't want to bother stocking / using heavier wire when necessary.

Sometimes people may run 22-4 to a simple contact sensor, but they only use two wires. The other two would be spares in the unlikely event the cable is partially damaged.

What I was saying is sometimes people run undersized 22-4 wire to a siren and hook green and black to negative and yellow and red to positive. Doubling the ampacity of a single 22awg wire. I've also seen two 22-4 cables run to a siren, quadrupling up the wires.