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