Alarm guide · Mitsubishi · Updated October 2026
Mitsubishi AL.32 alarm: Overcurrent
Mitsubishi AL.32 means current above the permitted level flowed in the servo amplifier output. Typical causes are a failed output stage, a shorted motor winding, a damaged motor cable, or a phase-to-phase short. Check the motor and cable before replacing the amplifier.
By Suresh Sankaran, founder of Star Automations, servo motor repair since 1998.
What the alarm means
Mitsubishi AL.32 means current above the permitted level flowed in the servo amplifier output. Typical causes are a failed output stage, a shorted motor winding, a damaged motor cable, or a phase-to-phase short. Check the motor and cable before replacing the amplifier.
Safe first checks
General guidance only. Follow the drive manual and your site's electrical safety rules. Power off, and let the DC bus discharge, before touching connectors.
- Power off and wait for the charge lamp to go out.
- Disconnect the motor and test motor and cable insulation to earth.
- Check the motor phases for a short between phases.
- Check the motor power connector for burn marks.
When to send it for repair
Send the amplifier when the motor and cable test good and the alarm stays. Send the motor too if its windings test bad. The amplifier is repaired at component level and tested with a motor.
See Mitsubishi servo motor repair, encoder repair and servo drive repair.
Questions
Can I clear the AL.32 alarm and keep running?
Not safely until the cause is found. An overcurrent alarm that clears and returns can damage the drive further or burn the motor. Check the motor and cable first. If they test good and the alarm returns, the drive needs repair.
Is it the motor, the cable or the drive?
Swap with a known-good cable first, then swap the motor to another axis if you can. If the alarm follows the motor, send the motor. If it stays on the axis with a good motor and cable, send the drive. We test both when you are not sure.
How long does repair take?
Emergency repair is done the same day where the fault and parts allow, urgent in 3 working days and standard in 7 working days, counted from when the unit reaches our bench and the quote is approved. Every unit returns with a printed test report.
Can I get an exchange unit?
If we hold a matching unit, Servo Swap ships a tested exchange unit while yours is repaired. Mark "line down" on the request form and add the part number.
Brand names identify the units we repair. Star Automations is an independent multi-brand repair company and is not an OEM service centre.