What is the standard voltage for residential irrigation controllers?

The standard voltage for residential irrigation controllers is 24 volts AC. This low voltage is commonly used in residential irrigation systems because it is safe and efficient for operating the various components of the system, such as valves and sensors, without posing a significant risk of electric shock.

Using 24 volts allows for longer wire runs and reduced power loss, making it effective for the typical distances between the controller and the various zones in a home landscape. This voltage level is suitable for both commercial and residential applications, which adds to its prevalence in the industry. It is also compatible with various irrigation equipment, allowing for ease of integration and replacement.

In contrast, higher voltages like 110 volts AC and 240 volts AC are used in more industrial or heavy-duty applications, where higher power is required, but they are not needed for the relatively low-power demands of residential irrigation systems. Similarly, while 12 volts AC might be used in some low-power applications, it is less commonly adopted for irrigation controllers, making 24 volts the recognized standard.