Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 241

8. TROUBLESHOOTING
8.3 Remedies for warnings
When the warning "The servo motor stops." described in the following table occurs, the servo-off occurs and
the servo motor stops. If any other warning occurs, operation can be continued but an alarm may take place or
proper operation may not be performed.
Remove the cause of warning according to this section. Use MR Configurator to refer to a factor of warning
occurrence.
Alarm No.: A.90 Name: Home positioning incomplete warning
Warning contents
Detailed
Detailed
display
Name
90.1 Home 1) Positioning operation was
position
return
incompletion
90.2 Home 1) Home position return
position
return
abnormal
completion
Alarm No.: A.91 Name: Servo amplifier overheat error
Warning contents
Detailed
Detailed
display
Name
91.1 Servo 1) The temperature in the
amplifier
inside
overheat
warning
2) Used beyond the
Alarm No.: A.96 Name: Home position setting error
Warning contents
Detailed
Detailed
display
Name
96.1 In-position 1) Droop pulses remaining
not reached
POINT
When any of the following alarms has occurred, do not resume operation by
switching power of the servo amplifier OFF/ON repeatedly. The servo amplifier
and servo motor may become faulty. If the power of the servo amplifier is
switched OFF/ON during the alarms, allow more than 30 minutes for cooling
before resuming operation.
Excessive regenerative warning (E0.1)
Servo amplifier overheat warning (91.1)
Overload warning 1 (E1. )
Parameter error (37. ) alarm and warnings are not recorded in the alarm history.
Home position return is not performed correctly.
Cause
performed without home
position return.
speed could not be
decreased to the creep
speed.
The temperature inside of the servo amplifier exceeds the warning level.
Cause
servo amplifier is high.
specifications of close
mounting.
Incorrectly finished after home position return operation.
Cause
are greater than the in-
position range setting.
The servo motor stops.
Checking method
Check if home position Home position
return was performed. return was not
performed.
Check the home The set value is
position return speed, incorrect.
the creep speed and
the travel distance after
proximity dog.
The servo motor does not stop.
Checking method
Check the ambient Ambient
temperature of the temperature is high.
servo amplifier. (over 55 )
Ambient
temperature is low.
Check the Used beyond the
specifications of close specifications.
mounting.
The servo motor stops.
Checking method
Check the number of In-position range or
droop pulses after more
home position return.
8 - 24
Result Action
Perform home position
return.
Set correctly and perform
home position return.
Result Action
Lower the ambient
temperature.
Check 2).
Use within the range of
specification.
Result Action
Remove the cause of
droop pulse occurrence.