Mitsubishi Electric Melservo-J2-JR SERIES Instruction Manual page 134

9. TROUBLESHOOTING
Display Name
A. 51 Overload 2
A. 52 Error excessive Droop pulse value of
Definition
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
Servo motor locked:
motor's input terminals U, V, W.
1s or more
3. Servo system is instable and
hunting.
4. Encoder faulty.
When the servo motor shaft is
rotated slowly with the servo off,
the cumulative feedback pulses
should vary in proportion to the
rotary angle. If the indication
skips or returns midway, the
encoder is faulty.
1. Acceleration/deceleration time
the deviation constant is too small.
counter exceeded
2. Torque limit value (parameter
80k pulses.
No.28) is too small.
3. Motor cannot be started due to
torque shortage caused by power
supply voltage drop.
4. Position control gain 1 (parameter
No.6) 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
9 - 10
Action
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.