Indicator light malfunction

1. Fault phenomenon:
After powering on the electric actuator, it was found that the power indicator light was not on, there was no feedback from the servo board, and the signal did not act.

Fault diagnosis and maintenance process:
Due to the power indicator light not being on, first check if the fuse tube is open. After checking that the fuse tube is intact and considering the fault phenomenon, it can be inferred that the fault may have occurred in the power supply part of the servo board. Then, check the power indicator light and use a multimeter to detect an open circuit in the indicator light. Replace the indicator light to troubleshoot.

Conclusion: An open circuit in the power indicator light can cause the entire servo board to malfunction.


2. Fault phenomenon: (discovered during debugging)
After the actuator of the electric actuator is powered on, a signal is given to turn it on but not to turn it off.
Fault diagnosis and maintenance process: First, carefully check the feedback circuit to confirm that there is no fault with the feedback signal. When the signal is turned on, the indicator light will light up, indicating normal operation. When the signal is turned off, the indicator light will not light up, indicating a problem with the thyristor part. First, check the indicator light and use a multimeter to check and find that the indicator light is open. Replace it and troubleshoot.

Conclusion: When the off and on indicator lights are not on (open circuit), the thyristor does not operate.

Resistance capacitance

1. Fault phenomenon:
After the electric actuator is powered on, given a signal (e.g. 75%), the actuator will fully open and then return to the designated position (75%).

Fault diagnosis and maintenance process:
Based on the above fault phenomena, the first thing to determine is which one is the problem with the servo board and actuator. Remove the servo board from the actuator and directly connect the power cord to terminals X5/1 and X5/4. The actuator will turn off in the direction of operation. Connect the power cord to terminals X5/1 and X5/2, and the actuator will turn on in the direction of operation. If the actuator does not operate normally, it indicates that the fault is on the actuator. Using a multimeter to measure the motor winding, it was found that there was an open circuit when measuring the resistance on both sides of the capacitor. After replacing it, the fault was resolved.

Conclusion: When encountering the above fault phenomena, the first step is to determine which part of the fault occurred, and finally determine the root cause.

2. Fault phenomenon:
After the actuator is powered on, a closing signal (4mA) is given. The actuator is fully opened first and then fully closed.

Fault diagnosis and maintenance process:
First, remove the servo board and directly power on the actuator to find that the original fault still exists. Check the resistance, the resistance value is normal, indicating that the resistance is not a problem. Check the motor winding, and it is found that the resistance value is normal, indicating that the motor is not a problem. Based on this fault, it is inferred that the capacitor may be damaged. Replace the capacitor and troubleshoot.

Conclusion: When this issue occurs, the first thing to suspect is resistance and capacitance.

other

1. Fault phenomenon:

As long as the AC220V power supply is provided on site, the protection switch will immediately activate (trip) and the actuator's safety relay will be burned.

Fault diagnosis and maintenance process:
Firstly, use a multimeter to check the motor winding on the actuator, and it is found that the resistance of the motor winding tends to zero, indicating that the motor has short circuited. Then, check the resistance at both ends of the brake, and the resistance tends to infinity, indicating that the brake is broken. Normally, it should be around 1.45K. The final solution is to replace the brake and motor with new ones, install the safety tube of the servo board, readjust, and restore normal operation.

Conclusion: This situation should be due to the motor being locked up after the brake was broken and not detected on site in a timely manner, resulting in the motor being stuck and heating for a long time, ultimately leading to insulation damage between the motor phases during operation.


2. Fault phenomenon:
The direction of action of the actuator is not controlled by the input signal.

Judgment and maintenance process:
First, check the two current limiting resistors and phase-shifting capacitors without any abnormalities. Use a multimeter to check the resistance value of the motor winding, and it is found that the resistance value of the motor is 1.45M Ω (and occasionally changes), indicating that the motor winding is incorrect. The final solution is to replace this motor.

3. Fault phenomenon:
The direction of action of the actuator is not controlled by the servo board.

Fault diagnosis and maintenance process:
Firstly, let the user use a multimeter to check the two current limiting resistors, phase-shifting capacitors, and the winding resistance of the motor. The user's inspection results are consistent with the final data we provide. The three factors that affect the direction of the actuator are ① the winding of the motor itself, ② the current limiting resistance, and ③ the phase shifting capacitance. Apart from these three factors, there is no other possibility.


4. Fault phenomenon:
No matter what signal is given on site, the motor will not operate,

Fault diagnosis and maintenance process:
Directly apply power between the motor windings, and the motor does not transmit power. Even after removing the brake, the motor still does not rotate. The resistance values of the motor windings are normal, and the handwheel rocker actuator operates normally. The test results are all normal, but the motor does not rotate when powered on. At this time, the rotor of the motor is suspected. When the motor is disassembled, it is found that the rotor cannot be turned by hand. It turns out that there is already a strong layer of dust between the rotor and the motor end cover. After removing this layer of dust, adding a little lubricating oil, and turning it by hand can be done. Reinstall the motor and install it in conjunction with the actuator, power on normally, and debug again.