For running 1000' of wire to an alarm device such as a siren, which wire gauge should you use or better?

• A. 12 AWG or better
• B. 16 AWG
• C. 18 AWG
• D. 14 AWG

Answer: (A)

Voltage drop on a long wiring run is the main factor at play. When you run power to a siren from 1000 feet away, the wire’s resistance causes part of the supply voltage to be lost as current flows through it. The thinner the wire, the higher its resistance, so more voltage is dropped before the siren sees power. That can leave the siren underpowered and not audible or reliable.

Different gauges have different resistances per thousand feet. For 12 AWG, the resistance is relatively low, so the voltage at the siren stays closer to what the power source provides even over a long distance. Thinner wires like 14, 16, or especially 18 AWG have progressively higher resistance, leading to a larger voltage drop at typical siren currents. In many cases, 18 AWG would drop enough voltage to impair operation, whereas 12 AWG keeps the voltage within an acceptable range.

So choosing 12 AWG or thicker minimizes voltage drop and ensures the siren operates properly over a 1000-foot run. If you can’t use 12 AWG, consider rerouting or splitting the run, or using a thicker gauge on the long leg to preserve voltage at the device.