Cause : Regenerative discharge comes when an issue with regenerative energy management. This occurs when the servo drive generates more energy than it can absorb during deceleration or braking. This excess energy, known as regenerative energy, needs to be dissipated to prevent damage to the drive.

"alarm 18" in panasonic servo drive indicate "Regenerative discharge". This means the energy generated during the deceleration or braking of the motor is not being dissipated properly. This could be due to issues with the regenerative resistor or the circuitry associated with it.

Here are some steps to troubleshoot and resolve the issue:

1. Check Regenerative Resistor:

• Ensure that the regenerative resistor is properly connected and functioning.
• Measure the resistance of the regenerative resistor to ensure it matches the specifications in the manual.
• Inspect the resistor for any visible damage or signs of overheating.

2. Inspect Wiring and Connections:

• Check the wiring between the regenerative resistor and the servo drive. Look for any loose, damaged, or disconnected wires.
• Verify that all connections are secure and free from corrosion.

3. Parameter Settings:

• Review the parameter settings in the servo drive related to regenerative braking and ensure they are correctly configured for your application.
• Parameters such as deceleration rates and braking times should be set appropriately to manage the regenerative energy.

4. Cooling and Ventilation:

• Ensure that the servo drive and regenerative resistor have adequate cooling and ventilation.
• Check for any blockages in cooling fans or vents and clean them if necessary.

5. Load Conditions:

• Assess the load conditions on the motor. Heavy loads or sudden changes in speed can generate excessive regenerative energy.
• Ensure that the mechanical system is not causing sudden deceleration or abrupt stops that the regenerative system cannot handle.

6. Inspect the Drive:

• Check the servo drive for any signs of internal damage or malfunction.
• If the drive has been subjected to harsh conditions or frequent overloads, internal components may be damaged.