Cause : Overcurrent during deceleration comes when the drive has detected an excessively high current while the motor is decelerating.

"E03.05" fault in inovance MD800 drive indicate "Overcurrent during deceleration". This means the drive is trying to slow down the motor too quickly, causing a surge in regenerative energy that the drive cannot handle.

Possible Causes:

1. Deceleration Time Too Short: A short deceleration time can cause the motor to stop too quickly, leading to a high regenerative current that the drive cannot dissipate.
2. Excessive Inertia: The motor might be connected to a load with high inertia, making it difficult to decelerate without generating significant regenerative energy.
3. Insufficient Braking Resistor: If the braking resistor is undersized or not functioning correctly, the drive might not be able to dissipate the regenerative energy effectively.
4. Incorrect Drive Settings: Parameters related to deceleration and braking might be incorrectly set, leading to improper handling of the regenerative energy.
5. Drive or Motor Fault: There could be an issue with the drive, motor, or cabling causing abnormal current during deceleration.

Troubleshooting Steps:

1. Increase Deceleration Time:

   • Lengthen the deceleration time in the drive’s parameter settings. A longer deceleration time reduces the regenerative current by allowing the motor to slow down more gradually.
   • Refer to the drive’s manual for appropriate deceleration time settings based on your application.

2. Check for High Inertia Loads:

   • If the motor is connected to a load with high inertia (e.g., a large flywheel or heavy equipment), consider increasing the deceleration time or adding an external braking resistor to handle the regenerative energy.
   • Ensure the load is not excessively heavy for the motor and drive configuration.

3. Inspect and Size the Braking Resistor:

   • Verify that a braking resistor is installed, appropriately sized, and functioning correctly. The braking resistor dissipates the regenerative energy generated during deceleration.
   • If necessary, upgrade to a larger or more capable braking resistor.

4. Review Drive Settings:

   • Double-check the drive parameters related to braking, such as the braking torque limit and dynamic braking settings, to ensure they are correctly configured.
   • Adjust the settings to optimize the deceleration process and minimize the risk of overcurrent.

5. Inspect the Drive and Motor:

   • Examine the drive, motor, and associated wiring for any signs of damage, wear, or loose connections that could contribute to irregular current flow.
   • Test the motor with another drive or the drive with another motor to identify if the issue is specific to one component.

6. Enable Current Limit Function:

   • If the drive supports it, enable the current limit function to automatically reduce the deceleration rate if an overcurrent condition is detected.