Common faults of electric control valves and their solutions

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Fault 1: The actuator does not move, but the power supply and indicator light of the control module are both on. Solution: Check whether the power supply voltage is correct ； Is the motor wire broken? ； Is there any broken wire from the end of the 10-core plug to each wire terminal? ； Are the plugs of the motor, potentiometer, and capacitor properly connected? ； Use the comparison and swapping method to determine whether the control module is functioning properly. Fault 2: The actuator does not move; the power light is on, but the signal light is not. Solution: Check whether the polarity of the input signal and other parameters are correct ； Use the comparison and swapping method to determine whether the control module is functioning properly. Fault 3: Improper setting of system parameters leads to frequent oscillation of the actuator. Solution: Improper tuning of the regulator parameters can cause the system to oscillate to varying degrees. In a single-loop control system, too small a proportional band, too short an integral time, and excessive differential time and differential gain can all cause system oscillation. Through systematic tuning, these parameters can be selected appropriately to maintain a stable speed in the loop. Fault 4: The actuator motor heats up rapidly, experiences oscillatory movement, and stops functioning within a short time. Solution: Use the 2V AC voltage setting to check whether there is any AC interference at the input terminal of the control module ； Check whether the signal wire is isolated from the power wire ； Are the potentiometers and their wiring in good condition? ； Check whether the feedback component is functioning properly. Fault 5: The actuator moves in a stepwise or crawling manner, with slow movement. Solution: Check whether the signal response time from the operator is correct. Fault 6: The actuator position feedback signal is too large or too small. Solution: Check whether the adjustments of the “zero” and “travel” potentiometers are correct ； Judge by replacing the control module. Fault 7: After the signal is applied, the actuator opens or closes fully, and the limit switch keeps operating. Solution: Check whether the function selection switch of the control module is in the correct position ； “Are the “zero” and “travel” potentiometers adjusted correctly? ； Judge by replacing the control module. Fault 8: Oscillation and humming of the actuator. Solution: This is mainly due to the sensitivity being set too high, resulting in a too small insensitive area; such high sensitivity causes the actuator’s feedback loop to become unstable and oscillate. The sensitivity potentiometer can be adjusted slightly counterclockwise to reduce the sensitivity ； The fluid pressure change is too large, resulting in insufficient thrust from the actuator ； If the control valve is selected to be too large, the valve tends to operate at a low opening degree. Fault 9: The actuator does not operate properly, but the motor does not stop even after the limit switch is activated. Solution: Check for any faults in the limit switch and its wiring ； Judge by replacing the control module. Fault 10: Actuator belt broken. Solution: Check whether the internal transmission mechanism of the actuator is damaged or stuck ； “Are the “zero” and “travel” potentiometers adjusted correctly? ； Whether the limit switch is correct.