Single seat electric control valve troubleshooting method

The performance of a single seat electric control valve will directly affect the quality of the entire adjustment system. Because the single-seat electric control valve is in direct contact with the media to be adjusted in the field, the working environment is very harsh, and therefore it is easy to produce various failures. In the production process, besides eliminating these faults at any time, regular maintenance and regular maintenance must be carried out. Especially for the use of a particularly bad control valve, it should pay more attention to maintenance and regular maintenance. Different forms of single seat electric control valve, its failure and its causes are not the same.

Fault 1: The actuator does not act, but the control module power supply and signal light are on.

Processing method: Check whether the power supply voltage is correct; whether the motor is disconnected; whether the ten-core plug is disconnected from the end to the end of each line; whether the motor, potentiometer, and capacitor are connected to each other are good; whether the control module is good is judged by the comparative interchange method.

Fault 2: Actuator does not move, power light is on and signal light is off.

Processing method: Check whether the polarity of the input signal is correct; use the comparative swap method to judge whether the control module is good.

Fault 3: Adjusting the system parameters causes the actuator to oscillate frequently.

Processing method: Adjusting the parameters of the regulator is not suitable, which will cause the system to produce different degrees of oscillation. For a single-loop control system, the proportional band is too small, the integral time is too short, and the differential time and differential gain are too large to cause system oscillation. It is possible to select these parameters reasonably through the method of system tuning so that the loop can maintain a stable speed.

Fault 4: The actuator motor heats quickly, oscillates and stops for a short time.

Treatment method: Use the AC 2V voltage profile to measure whether the input of the control module is AC interference; check whether the signal line is isolated from the power line; whether the potentiometer and potentiometer wiring are good; whether the feedback component is operating normally.

Fault 5: Actuator movements are stepping, crawling, and slow.

Treatment method: Check whether the signal movement time from the operator is correct.

Fault 6: Actuator position feedback signal is too large or too small.

Treatment method: Check whether the "zero" and "stroke" potentiometer adjustments are correct; replace the control module judgment.

Fault 7: After the signal is added, the actuator is fully open or fully closed, and the limit switch is not stopped.

Treatment method: Check whether the function selection switch of the control module is in the correct position; whether the “zero” and “stroke” potentiometers are adjusted correctly; replace the control module to judge.

Fault 8: The actuator oscillates and tweets.

Treatment method: Mainly because the sensitivity is adjusted too high, the insensitivity zone is too small, and it is too sensitive. As a result, the small loop of the actuator can not be stable and oscillate. The sensitivity of the counter-clockwise fine-tuning potentiometer reduces the sensitivity; the fluid pressure changes too much and the actuator thrust is too high. Inadequate; large selection of control valves, valves often work at a small opening.

Fault 9: The actuator does not operate normally, but the motor does not stop after the limit switch is actuated.

Treatment method: Check whether the limit switch and the limit switch wiring are faulty; replace the control module to judge.

Fault 10: The actuator belt is broken.

Treatment method: Check whether the actuator internal transmission is damaged or not; "Zero" and "travel" potentiometer adjustment is correct; limit switch is correct.

In order to avoid the interference of the power line, single-seat electric control valve signal cable adopts shielded cable and is shielded from the power cable; the power supply wiring must have enough capacity to meet the requirements of the actuator rated current and starting current; install the ground wire and connect the power supply When disconnecting the signal line, the power should be cut off first to prevent electric shock. The connection terminal of the power supply, creepage distance and clearance should be greater than 8mm; regular inspection of the aging problem of the seal ring, timely replacement; , prevent short circuit.