Mitsubishi Melservo Alarm Analysis
Mitsubishi MR-J3 and MR-J4 servo drives are common in CNC machinery. Understanding their alarm codes is key to diagnosing issues.
1. AL 16 - Encoder Communication Error
The drive has lost communication with the motor encoder. Causes: Damaged encoder cable, faulty connector, or a failure in the drive's line receiver circuit. Remedy: Check the cables, test the 5V encoder supply rail, and replace the differential line receiver ICs on the drive's interface board if needed.
2. AL 32 - Overcurrent
The output current has exceeded the safe limit. Causes: Output short circuit, motor grounding fault, or damaged power modules. Remedy: Perform a static diode test on the drive's power stage. Replace shorted IGBT modules and driver ICs as required.