Mitsubishi Electric Melservo-J2-SUPER series Instruction Manual page 234

11. TROUBLESHOOTING
Display Name
AL.50 Overload 1
AL.51 Overload 2
AL.52 Error excessive The droop pulse
Definition
Load exceeded 1. Servo amplifier is used in excess of
overload protection its continuous output current.
characteristic of
servo amplifier.
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.
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.
Machine collision or 1. Machine struck something.
the like caused max.
output current to
2. Wrong connection of servo motor.
flow successively for
Servo amplifier's output terminals
several seconds.
U, V, W do not match servo motor's
Servo motor locked:
input terminals U, V, W.
1s or more
3. Servo system is instable and
During rotation: 2.5s
hunting.
or more
4. Encoder faulty.
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. Acceleration/deceleration time
value of the constant is too small.
deviation counter
2. Internal torque limit 1 (parameter
exceeded 2.5
No.28) is too small.
rotations.
3. Motor cannot be started due to
torque shortage caused by power
supply voltage drop.
4. Position control gain 1 (parameter
No.7) value is small.
5. Servo motor shaft was rotated by
external force.
6. Machine struck something.
7. Encoder faulty
8. Wrong connection of servo motor.
Servo amplifier's output terminals
U, V, W do not match servo
motor's input terminals U, V, W.
Cause
Checking method
Checking method
11 - 7
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.
Increase the acceleration/deceleration
time constant.
Increase the torque limit value.
1. Review the power supply capacity.
2. Use servo motor which provides larger
output.
Increase set value and adjust to ensure
proper operation.
1. When torque is limited, increase the
limit value.
2. Reduce load.
3. Use servo motor that provides larger
output.
1. Review operation pattern.
2. Install limit switches.
Change the servo motor.
Connect correctly.