The unit Yaskawa CIMR-G5C4011 arrived with the complaint “motor jerking”. Initial testing immediately revealed abnormal behavior beyond simple parameter issues.

In forward direction, the motor ran smoother and reached a higher speed at the same reference value than in reverse. In reverse direction, the motor showed jerking motion, reduced speed and unstable current behavior. During deceleration from forward motion, the motor did not stop properly and continued running until the inverter shut down with the error “CF out of control”.

This behavior is characteristic of asymmetric control. Since forward and reverse control paths are identical in software, the root cause had to be hardware related.

After complete disassembly and cleaning, detailed analysis of the current feedback paths revealed slight deviations between individual channels under load. Although small, these deviations were sufficient to destabilize the control loop during direction changes.

The affected assemblies were repaired, measurement channels recalibrated and the unit tested extensively under realistic load conditions with repeated direction changes and braking cycles.

After repair, forward and reverse operation were fully symmetrical. The motor stopped correctly and the CF fault no longer occurred.

Preventive Measures

Regular inspection of cooling and fan operation
Stable and clean power supply
Avoid continuous operation at braking limits
Regular inspection of power terminals
Monitor unusual noise or vibration during direction changes

Conclusion

This case demonstrates that complex drive faults cannot always be solved by parameter adjustments. Asymmetric motor behavior is a strong indicator of hardware related control issues. Accurate diagnostics and realistic testing are essential for a reliable and lasting repair.

Further information such as price and delivery time for:
Yaskawa CIMR-G5C4011 Varispeed 6161G5

More details about our Yaskawa repair expertise can be found here: Yaskawa Varispeed repairs by Industrypart

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Technical Specifications

Operating Environment and Compatible Equipment

The Yaskawa CIMR-G5C4011 is commonly used in industrial applications requiring precise speed control of asynchronous motors. Typical applications include machine tools, conveyor systems, winding machines, test benches and special machinery with frequent direction changes and braking cycles.

Functional Description

The Varispeed 6161G5 is a vector controlled inverter with separate power and control sections. Motor currents are continuously measured and fed back into the control logic. Based on these signals, the control board generates the PWM patterns for the power stage.

Forward and reverse operation are processed identically by the control system. Any directional difference therefore indicates a hardware related imbalance in the current measurement or signal processing paths.

Alarms and Troubleshooting (excerpt)

Components