Mitsubishi melservo-j2 series Instruction Manual page 210

11. TROUBLESHOOTING
Display Name
A.51 Overload 2
A.52 Error excessive
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 U,
several seconds.
V, W do not match servo motor's input
Servo motor locked:
terminals U, V, W.
1s or more
3. Servo system is instable and hunting.
4. Encoder faulty.
Droop pulse value of 1. Acceleration/deceleration time constant
the deviation counter is too small.
exceeded 80k pulses.
2. Torque limit value (parameter 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.7) value is small.
5. Servo motor shaft was rotated by
external force.
6. Machine struck something.
Cause
Checking method
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.
11 - 7
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.