Key points for testing intelligent valve actuators

Before removing a non-working valve, a technician should test the valve's control box. When the tank's pressure switch detects low water pressure, power to the control box is switched on. Once the water pressure reaches the switch's high pressure limit, the switch opens, cutting off power. Oil valves with control boxes have start and run circuits. When started, the control box sends power to the valve motor through the start circuit. Once the valve motor reaches operating speed, the control box switches power to the run circuit.

Checking the control box wiring diagram can identify the electrical terminals and their functions. The wires from the pressure switch are connected to the electrical input terminals, which are usually called "L1" and "L2." The wires connected to the oil valve motor are connected to the terminals with start, run, and neutral functions, which are usually marked "S," "R," and "N." The wire connected to the green screw grounds the oil system. Also, check the control panel's wires, wire connections, relays, and capacitors. If there are burnt or damaged wires or parts, they should be replaced. All wire connections should be tightened with the correct screwdriver. If there are leaks or swelling in the capacitor, the capacitor should be replaced.