What is the typical operating voltage for irrigation controllers and solenoids?

• A. 24 Volts AC
• B. 120 Volts AC
• C. 12 Volts DC
• D. 240 Volts AC

Answer: (A)

The typical operating voltage for irrigation controllers and solenoids is 24 volts AC. This low-voltage supply comes from a small transformer in the controller, stepping down from household mains to a safe, manageable level. Solenoids are designed to be energized by 24 VAC, which provides reliable valve operation while drawing relatively modest current. The low voltage keeps wiring simple and cost-effective and reduces safety concerns for outdoor use, even when you have multiple valves on the same controller.

Other voltages aren’t as common in standard irrigation setups. 120 or 240 VAC would require heavier-duty equipment and insulated wiring, increasing costs and safety considerations. 12 V DC is not typical for most irrigation solenoids, as the standard solenoids are designed for AC operation; some specialized or battery-powered configurations may use DC, but the mainstream systems rely on 24 VAC.