Siemens · SINAMICS G120
The DC-link maximum voltage controller has been deactivated. This typically happens if the main supply voltage is consistently too high, if the motor is regenerating power back to the drive due to an active load, or during deceleration with high inertial loads. This can lead to excessive DC link voltage and potential damage to the drive components if not managed.
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1. Measure the incoming supply voltage at terminals L1, L2, L3 and verify it is consistently within the drive's specified operating range (e.g., 400V +/- 10%).
2. Monitor the DC-link voltage (r0026) during operation, especially during deceleration, to identify if it's consistently near or exceeding the Vdc-max threshold.
3. If regenerative operation is present, verify the braking resistor's connection at terminals R1, R2 and measure its resistance to ensure it matches the specified value.
4. Check parameters P1240 (DC-link overvoltage threshold) and P1243 (Braking chopper threshold) to ensure they are configured correctly for the application and any connected braking components.
5. Increase deceleration ramp times (e.g., P1121, P1130) to reduce the amount of regenerative energy generated during motor slowdown.