Mitsubishi Electric Melservo-J4 Instruction Manual page 125

Alarm No.: F7 Name: Machine diagnosis warning
 There is a possibility that the equipment connected with the servo motor is malfunctioning.
Alarm content
Detail Detail name Cause
No.
F7.1 Vibration failure (1)
prediction
warning
(2)
F7.2 Friction failure (1)
prediction
warning
(2)
F7.3 Total travel (1)
distance failure
prediction
warning
Check method
The servo system is Check if the gain is
unstable and changed after the
oscillating. vibration failure
prediction function is
enabled.
The vibration during Check that the vibration
servo motor operation level during servo motor
increased because of operation increased from
deterioration of that during the initial
equipment parts. operation.
Changes in Check that environment
environment affected conditions such as
equipment friction. ambient temperature has
been changed from that
of the initial operation.
Deterioration of Check that the friction
equipment parts torque at rated speed
affected equipment has been changed from
friction. that of the initial
operation.
The servo motor total Check if the threshold is
travel distance exceeds set correctly.
the threshold.
Check result
The gain was changed.
The gain was not
changed.
The vibration level during
servo motor operation
increased by 5% or lower
from that during the initial
operation.
The vibration level during
servo motor operation
increased by 5% or
higher from that during
the initial operation.
The usage environment
has been changed.
The usage environment
is not changed.
The friction torque at
rated speed is not
changed from that of the
initial operation.
The friction torque at
rated speed has been
changed from that of the
initial operation.
The threshold is not set
correctly.
The threshold is set
correctly.
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Action Target
Adjust the servo gain [GF]
with the auto tuning. Set
the machine resonance
suppression filter.
Check (2).
Set a larger threshold
multiplication for vibration
failure prediction ([Pr.
PF40] "_ _ x _") and
restart the equipment.
Check and maintain the
equipment and replace
parts as necessary.
Reset the threshold to
set a new one.
Check (2).
Set a larger threshold
multiplication for friction
failure prediction ([Pr.
PF40] "_ _ _ x") and
restart the equipment.
Check and maintain the
equipment and replace
parts as necessary.
Set the parameters so
that the value of "[Pr.
PF34] × [Pr. PF41]" is
approximately the same
as the rated life and
restart the equipment.
Check the equipment.
After replacing the
equipment, reset the
servo motor total travel
distance.
1.5 Remedies for warnings
1
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