Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 238

8. TROUBLESHOOTING
Alarm No.: A.52 Name: Error excessive
Description
Detailed Detailed
display Name
52.3 Droop 1) Servo motor power cables
pulses
excessive
2) Incorrect connection with
3) Incorrect connection of the
4) Torque limit value is small. Check the torque limit
5) The work collided against
6) Torque shortage
7) Servo motor cannot be
8) Acceleration/deceleration
9) Gain adjustment is not
10) Estimation of the load to
11) Position loop gain value is
12) Servo motor is rotated by
13) Encoder faulty
The droop pulse between the command position and the current position exceeds the alarm level.
Cause
are not connected.
(missing phase)
the servo motor
encoder cable
the structural part.
started due to torque
shortage caused by power
supply voltage drop.
time constant is short.
made well.
motor inertia moment ratio
is not estimated well.
small.
external force.
Checking method
Check the wiring. Not connected
(missing phase).
No error.
Check the wiring of U, Incorrect connection. Correct the wiring.
V and W.
Correct connection.
Check if the encoder Incorrect connection. Correct the wiring.
cable is connected
Correct connection.
correctly.
Torque limit value is
value. small.
Normal range
Check if the work Collided.
collided against the
structural part.
Did not collide.
Check if the torque is Saturated
saturated.
Not saturated
Check the value of The value is "1"
status display Pn (bus (undervoltage) or
voltage). "2" (low voltage).
The value is "4"
(high voltage) or "5"
(overvoltage).
Check if the alarm occurs Alarm does not
after the deceleration time occur.
constant is increased.
Alarm occurs.
Check the load to Load to motor inertia
motor inertia moment moment ratio is
ratio. normal.
Load to motor
inertia moment ratio
is not normal.
Check if the alarm Alarm does not
occurs after changing occur.
the load to motor inertia
Alarm occurs.
moment ratio manually.
Check if the alarm Alarm does not
occurs after the position occur.
loop gain is changed.
Alarm occurs.
Measure the actual The servo motor is
position on the servo rotated by an
lock status. external force.
Servo motor is not
rotated by an
external force.
Check if the alarm Alarm does not
occurs after replacing occur.
with the servo
operating normally.
8 - 21
Result Action
Correct the wiring.
Check 2).
Check 3).
Check 4).
Increase the torque limit
value.
Check 5).
Check the operation
pattern.
Check 6).
Reduce load.
Check operation pattern.
Replace the servo motor
to one that provides larger
output.
Check 7).
Check the power supply
voltage.
Check 8).
Check operation pattern.
Check 9).
Use the manual mode to
make gain adjustment.
Check 10).
Check the load to motor
inertia moment ratio.
Check 11).
Check the position loop
gain.
Check 12).
Check the machine.
Check 13).
Replace the servo motor.