When Yaskawa inverter encounters an overvoltage (OV) fault, the following steps can be taken to solve it:
1. Preliminary inspection and /confirm/iation
Observe the fault symptoms:
Pay attention to the indicator light and display on the inverter to see if there is an alarm message of overvoltage fault.
Record the time, frequency, and details of faults.
Check the power supply voltage:
Use a voltmeter to measure the voltage of the input power supply and ensure that it is within the rated voltage range of the inverter.
If the power supply voltage is too high, adjust the power supply voltage or install a voltage regulator.
2. Troubleshooting and cause analysis
Slow down time is too short:
If the deceleration time is too short, the regenerative energy flowing from the motor to the inverter will be too large, resulting in overvoltage failure.
Increase the set value of deceleration time parameters (such as C1-02, C1-04, C1-06, C1-08).
Or a brake resistor or brake resistor unit is connected to the inverter to consume excess regenerative energy.
Acceleration time is too short:
Too short acceleration time may also lead to overvoltage failure.
Increase the set value of the acceleration time parameter, such as C2-02.
Use the S-word acceleration and deceleration function to make the acceleration process smoother.
Large brake load:
If the braking load is large, the inverter may produce overvoltage during braking.
A brake resistor or brake resistor unit is installed on the inverter to absorb energy during braking.
There is surge voltage mixed in the input power supply:
The surge voltage may cause the inverter overvoltage fault.
Install a DC reactor to reduce the impact of surge voltage on the frequency converter.
Motor grounding short circuit:
Check whether the power cable, trunk terminal, and motor terminal box of the motor are short-circuited to the ground.
After the grounding short-circuit fault is rectified, switch on the power supply again.
Inverter internal component damage:
Check whether the internal components of the inverter are damaged, such as the rectifier bridge, filter capacitor, etc.
If damaged, replace damaged components.
PG cable problems:
Check whether the PG cable is broken or connected incorrectly.
Repair the broken line or reconnect the cable correctly.
Noise interference:
Keep the output line of the inverter away from the noise source to reduce noise interference to the PG cable.
3. Parameter adjustment and optimization
Adjust related parameters:
Adjust the relevant parameters of the inverter according to the actual situation, such as L3-04 (stall prevention function selection in deceleration), L3-11 (overvoltage suppression function selection), etc.
Adjust the load inertia ratio parameters (such as L3-25) to adapt to different load conditions.
Speed search related parameters:
If the frequency converter has an overvoltage fault during the speed search process, the speed search retry function can be reset to be effective.
Adjust the speed search operation current (such as b3-02) and speed search deceleration time (such as b3-03).
4. Preventive measures and follow-up maintenance
Strengthen equipment maintenance:
Regularly clean and inspect the frequency converter to ensure that the equipment is in good working condition.
Timely replacement of aging or damaged components to prevent failure.
Optimize the operating environment:
Ensure that the temperature and humidity of the operating environment meet the equipment requirements.
Avoid the frequency converter running in overload or overheating state for a long time.
Train operators:
Train the operators to familiarize them with the operating procedures and safety requirements of the frequency converter.
Improve operators' troubleshooting and emergency handling capabilities.