In irrigation controller wiring, the loop from the controller to the valve and back is commonly known as what?

• A. Power circuit
• B. Electrical circuit
• C. Control loop
• D. Ground path

Answer: (B)

When a valve is energized, current needs a complete path to flow. The loop from the irrigation controller out to the valve and back forms an electrical circuit—a closed path that includes the two conductors and the valve coil as the load. This is why it’s described as an electrical circuit: it describes the complete path that allows current to travel and energize the valve. It isn’t a ground path, since return current isn’t going to earth ground, and it isn’t a control loop in the automation sense, which implies sensing and feedback. It’s more precise than simply a power circuit, because it emphasizes the complete circuit needed for current to flow and energize the valve.