AL001 Over Current Fault in Delta ASDA-B2 Servo Drive
AL001 Over Current in the Delta ASDA-B2 Servo Drive indicates that the drive has detected an output current exceeding the allowable protection limit. The servo drive continuously monitors the motor current to protect the power module (IGBTs) and motor. If excessive current is detected, the drive immediately trips with Alarm AL001 to prevent damage to the inverter and motor.
This fault generally indicates a problem with the motor wiring, output circuit, power module, parameter settings, or motion command, rather than a fault with the feedback encoder.
Possible Causes
- Output short circuit.
- Motor cable short circuit.
- Exposed motor cable conductors touching each other or ground.
- Incorrect motor wiring.
- Incorrect phase sequence.
- Faulty motor insulation.
- Damaged motor cable.
- IGBT module failure.
- Abnormal heat sink temperature affecting the IGBT.
- Incorrect servo parameter settings.
- Acceleration time set too short.
- Excessive acceleration or deceleration command.
- Sudden load impact.
- Mechanical jam or locked motor shaft.
- Servo drive hardware failure.
Solutions
- Eliminate any short circuit on the drive output.
- Ensure no exposed metal conductors are touching each other or ground.
- Inspect the motor cable for insulation damage.
- Rewire the motor according to the Delta wiring diagram.
- Verify correct motor phase connections.
- Check the motor for winding short circuits.
- Restore servo parameters to their factory default values if parameter settings are suspected.
- Gradually readjust parameters after restoring defaults.
- Increase the acceleration and deceleration times.
- Use smoother motion commands.
- Apply a command filter to reduce sudden command changes.
- If the IGBT module is suspected to be faulty, contact Delta service.
- Replace or repair the drive if the power module has failed.
Additional Information
The Delta ASDA-B2 Servo Drive continuously monitors its output current during operation.
When the output current exceeds the protection threshold, the drive immediately disables the output and displays AL001 Over Current.
According to Delta, the most common causes include:
- Output short circuit.
- Incorrect motor wiring.
- IGBT abnormality (often accompanied by abnormal heat sink temperature).
- Incorrect control parameter settings.
- Excessively fast acceleration commands.
Delta recommends:
- Eliminating any short circuit.
- Rewiring the motor according to the user manual.
- Restoring parameters to their default values and readjusting them gradually.
- Using less aggressive motion commands or applying command filtering.
- Returning the drive for repair if an internal IGBT failure is suspected.
Unlike an overload alarm, AL001 is an instantaneous protection fault designed to protect the drive's power electronics from excessive current.
Common Symptoms
- Servo drive displays AL001 Over Current.
- Motor stops immediately.
- Servo output is disabled.
- Fault occurs immediately after enabling the servo.
- Fault occurs during rapid acceleration.
- Fault appears when the motor starts moving.
- Drive trips repeatedly under heavy load.
- Abnormal motor current is observed.
- Heat sink temperature may be high.
- Drive cannot be reset until the fault condition is removed.
Recommended Troubleshooting Sequence
- Disconnect power to the servo drive.
- Inspect the motor cable for short circuits.
- Check for exposed conductors.
- Verify motor wiring matches the user manual.
- Measure motor winding insulation.
- Inspect the motor for mechanical binding.
- Restore servo parameters to factory defaults if necessary.
- Gradually adjust parameter settings.
- Increase acceleration and deceleration times.
- Apply a command filter if motion commands are abrupt.
- Monitor motor current during testing.
- Check for abnormal heat sink temperature.
- If an IGBT fault is suspected, discontinue operation.
- Repair or replace the drive if necessary.
- Contact Delta technical support if the fault persists.
Over Current Check Table
| Check Point | Action |
|---|---|
| Drive output | Check for short circuits |
| Motor cable | Inspect insulation and exposed conductors |
| Motor wiring | Verify correct wiring according to the user manual |
| Motor winding | Check insulation and resistance |
| Mechanical load | Verify motor rotates freely |
| Servo parameters | Restore defaults if necessary |
| Acceleration time | Increase to reduce current peaks |
| Motion command | Use smoother commands or apply filtering |
| Heat sink temperature | Check for abnormal heating |
| IGBT module | Inspect or replace if defective |
| Delta technical support | Contact if the fault remains after inspection |
Preventive Maintenance Tips
- Inspect motor cables regularly for insulation damage.
- Ensure motor wiring follows the Delta wiring diagram.
- Prevent exposed conductors from contacting each other or ground.
- Use appropriate acceleration and deceleration times for the application.
- Apply command filtering for rapid position or speed changes.
- Periodically inspect cooling fans and heat sinks to maintain proper cooling.
- Monitor motor current trends during normal operation.
- Keep the servo drive free from dust, oil, and moisture.
- Use only Delta-approved replacement components.
- Record recurring AL001 faults to assist long-term diagnostics.
Proper inspection of the motor wiring, output circuit, IGBT power module, servo parameters, and motion command profile, along with eliminating short circuits and using appropriate acceleration settings, will help prevent recurring AL001 Over Current faults in Delta ASDA-B2 servo drives, ensuring reliable motor control, effective protection of the power electronics, and dependable long-term operation of the servo system.
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