When running thermostat wire over a distance of 90 feet, which gauge should be used to minimize voltage drop?

To minimize voltage drop over a distance of 90 feet in a thermostat wire application, utilizing a wire gauge with greater diameter is ideal. The lower the gauge number, the thicker the wire, which generally offers less resistance to the flow of electricity. Thicker wires like 14 AWG will have the least resistance, thus experiencing a smaller voltage drop compared to thinner wires.

In this scenario, 16 AWG is a suitable choice. It strikes an appropriate balance between size and performance for the distance involved, ensuring that the voltage drop remains within acceptable limits for the thermostat's operational requirements. For distances such as 90 feet, using 16 AWG is effective in maintaining system efficiency and reliability.

While finer wires (such as 18 AWG or 20 AWG) would be less effective as they would incur a greater voltage drop across the same distance. Consequently, they may not provide enough voltage to operate the thermostat efficiently, potentially leading to malfunctions or erratic behavior in temperature control. Thus, 16 AWG is positioned as an adequate gauge for minimizing voltage drop in this specific application.