Alarm codeAL.51
Overload 2 occurs due to machine collision, incorrect motor terminal connections, or unstable servo operation causing hunting. The manual's first action is: “Power OFF→ON”
- Model
- Mitsubishi Electric MR-J2S-A
- Display shows
- Overload 2 (AL.51)
- Type
- Alarm code
- Source
- Manual p. 69
What AL.51 means
Overload 2 p. 200
Common causes
- 1. Machine struck something. p. 200
- 2. Wrong connection of servo motor. Servo amplifier's output terminals U, V, W do not match servo motor's input terminals U, V, W. p. 200
- 3. Servo system is unstable and hunting. p. 200
- 4. Encoder faulty. p. 200
What to do
- Power OFF→ON p. 200
- Press "SET" on current alarm screen. p. 200
- Alarm reset (RES) p. 200
- 1. Review operation pattern. 2. Install limit switches. p. 200
- Connect correctly. p. 200
- 1. Repeat acceleration/deceleration to execute auto tuning. 2. Change auto tuning response setting. 3. Set auto tuning to OFF and make gain adjustment manually. p. 200
- Change the servo motor. p. 200
Before you service the product, read the safety instructions in the manual p. 3.
If AL.51 is still not resolved
- contact service / dealer p. 3 “Do not attempt to install, operate, maintain or inspect the servo amplifier and servo motor until you have read through this Instruction Manual, Installation guide, Servo motor Instruction Manual and appended documents carefully and can use the equipment correctly.”
- contact service / dealer p. 4 “Do not attempt to wire the servo amplifier and servo motor until they have been installed. Otherwise, you may get an electric shock.”
This page summarises what the manufacturer’s manual says about AL.51; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with Mitsubishi Electric. Found a mistake? Report an error.