long runs 22/4

[programmergeek]

I have a house we are wireing and the runs will be quite long up to maybe 500' the customer will pay for 18/4 wire but is there a need or should we just stick to the standard 22/4 for all the common sensors like occupancy/smoke/co2/motion/door etc? Anyone ever have a need to go thicker on the common sensors?

 

[Sandpiper]

I have a house we are wireing and the runs will be quite long up to maybe 500' the customer will pay for 18/4 wire but is there a need or should we just stick to the standard 22/4 for all the common sensors like occupancy/smoke/co2/motion/door etc? Anyone ever have a need to go thicker on the common sensors?

1000 ft of 22AWG wire has a resistance of about 16 ohms. A device such as a motion detector uses about 20mA of current so this will give a voltage drop of 0.32 volts---- No concern whatsoever for sensor devices. For sirens, if you have long runs, then an upgrade in wire is probably necessary. If the panel power supply wire is long, then it definitely needs an upgrade. Also, if you have multiple smokes or other power using devices on a long run, and upgrade would be suggested there.

 

[russban]

I have a house we are wireing and the runs will be quite long up to maybe 500' the customer will pay for 18/4 wire but is there a need or should we just stick to the standard 22/4 for all the common sensors like occupancy/smoke/co2/motion/door etc? Anyone ever have a need to go thicker on the common sensors?

Both the Honeywell Vista and GE Concord manuals state the 22/4 is OK up to 1000' for sensors but for keypads GE says 300' and Honeywell says 450'. I don't know what panels you are using but my guess is that 22/4 would be OK.

 

[BraveSirRobbin]

I'm guessing the keypads are more limited in distance because of communications issues, unlike plain sensors, which just use resistance. I also agree with Sandpiper, any large current draws such as strobes might want a larger gauge of wire.

 

[pbeaulieu]

If you are not sure and the total cost difference between 22/4 and 18/4 is small then why take the chance? The 18/4 wire is a bigger and that maybe a problem.

 

[Del91574]

95% of the common installs can be done using 22/4

As stated, large power draws like strobes, should always be in a heavier AWG. System speakers should also be in a heavier AWG as well.

Unpowered devices, like contacts, etc. generally are harder to work with using wire like 18 AWG.

Data devices (polling loop, multiplex, expanders, etc.) vary by manufacturer, but usually will benefit from a heavier AWG if they are going to be installed at great distances. Pay attention to what each manufacturer says about shielded cable and data runs however. Sometimes using the manufacturer's expansion and wiring back to those units and installing separate power supplies in the field can simplify the wiring methods and AWG's needed to make it all work properly.

Fire alarm, though not clearly stated in code, is traditionally run in 18 AWG. CO detectors and their wiring need to be addressed with the AHJ as to if they are considered a life safety device/system and need the same or normal system wiring.