For a 1000-foot run of wire to a remote bell or siren, what wire gauge is required?

• A. 12 AWG or better
• B. 18 AWG
• C. 8 AWG
• D. 4 AWG

Answer: (A)

Long runs require choosing a conductor size that keeps enough voltage at the remote device. For a 1000-foot run to a bell or siren, the wire’s resistance adds up, and current flowing to the device causes voltage to drop along the length. The goal is to minimize that drop so the siren still sees a usable voltage when it activates.

12 AWG has relatively low resistance, roughly 1.6 ohms per 1000 feet per conductor. with a round trip of about 2000 feet, that’s about 3.2 ohms total. At typical siren currents, this keeps the voltage at a usable level. An 18 AWG wire, by contrast, has about 6.4 ohms per 1000 feet, giving a loop resistance of around 12.8 ohms for the same run, which can drop several volts and may prevent the siren from operating reliably. Very thick wires like 8 AWG or 4 AWG are unnecessarily large for this application and add cost, even though they would work.

So, 12 AWG or thicker is required to ensure the remote bell or siren receives enough voltage over a 1000-foot run.