Repair of common faults of Lenze servo drives
1) OC5 failure.
OC5 fault should be a fault phenomenon that we often encounter in the 8220 8240 series inverter. OC5 is the overload of the inverter, and the overload detection is generally done by the Hall sensor, which detects the current of the two phases of the UV, and then judges whether the inverter is overloaded by the two inputs or the gate COMOS circuit. The failure point of OC5 is usually caused by the damage of the sensor and the damage of the gate circuit, the Hall sensor is susceptible to the influence of the environment, and the drift of the operating point occurs, and the gate circuit is often damaged due to the impact of the working voltage and input signal. Replacing a damaged device should be able to troubleshoot such faults.
2) Output phase loss.
The lack of phase of the output is also one of the failures that we often encounter. We all know that it is impossible to drag the three-phase AC asynchronous motor in the state of phase loss, and there will be an overcurrent alarm in the case of dragging the motor, and the 3-phase output voltage is measured after disconnecting the motor, and the 3-phase output voltage is often relatively different, at this time, the first thing should be to check whether the power module is damaged and whether the driving waveform is normal. A common phenomenon encountered in the Lenze 8240 series drives is that the drive circuit is voltageless. The difference between the 8240 series inverter and other inverters is that the driving power supply is not directly supplied by the switching power supply, and there is an isolation between the driving circuit and the switching power supply. So we also have to check if there is a problem with the isolation transformer. Troubleshooting the above should determine whether the power supply to the drive circuit is normal.