Mitsubishi Electric MELSERVO-J2-Super Series Instruction Manual page 280

12. TROUBLESHOOTING
Display Name
AL.50 Overload 1 Load exceeded
overload protection
characteristic of
servo amplifier.
Machine collision or
AL.51 Overload 2
the like caused max.
output current to
flow successively for
several seconds.
Servo motor locked:
During rotation:
Definition
1. Servo amplifier is used in excess of
its continuous output current.
2. Servo system is instable and
hunting.
3. Machine struck something.
4. Wrong connection of servo motor.
Servo amplifier's output terminals
U, V, W do not match servo motor's
input terminals U, V, W.
5. Encoder faulty.
Checking method
When the servo motor shaft is
rotated with the servo off, the
cumulative feedback pulses do
not vary in proportion to the
rotary angle of the shaft but the
indication skips or returns midway.
1. Machine struck something.
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.
1s or more
3. Servo system is instable and
hunting.
2.5s or more
4. Encoder faulty.
Checking method
When the servo motor shaft is
rotated with the servo off, the
cumulative feedback pulses do
not vary in proportion to the
rotary angle of the shaft but the
indication skips or returns midway.
Cause
12 - 9
Action
1. Reduce load.
2. Review operation pattern.
3. Use servo motor that provides larger
output.
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.
1. Review operation pattern.
2. Install limit switches.
Connect correctly.
Change the servo motor.
1. Review operation pattern.
2. Install limit switches.
Connect correctly.
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.
Change the servo motor.