Yaskawa MP940 Reference Manual - Manual (Page 394)

MotionSuite™ MP940 Machine Controller Reference Manual Troubleshooting
10-41
Servo motor moves
momentarily, then
stops. Servo motor or encoder
wiring incorrect. — Refer to Chapter 3, and
correct the wiring.
Suddenly stops during
operation and does not
restart. Alarm reset signal (ALM-
RST) is turned ON
because an alarm
occurred. — Remove cause of
alarm.Turn alarm reset sig-
nal (ALM-RST) from ON to
OFF.
Servomotor speed
unstable. Wiring connection to
motor defective. Check connection of
power lead (U, V, and W
phase) and encoder con-
nectors. Tighten any loose termi-
nals or connectors.
Servo motor vibrates
at approximately 200 ~
400Hz. Speed loop gain value too
high. — Reduce user parameter
Pn100 (Speed Loop Gain)
setting.
Speed/position reference
input lead too long. — Minimize length of speed/
position reference input
lead, with impedance not
exceeding several hun-
dred Ohms.
Speed/position reference
input lead is bundled with
power cables. — Separate reference input
lead at least 30cm from
power cables.
High rotation speed
overshoot on starting
and stopping. Speed loop gain value too
high. — Reduce user parameter
Pn100 (Speed Loop Gain)
setting.
Integral Time Constant
(Pn101) is too large.
Servo motor over-
heated. Ambient temperature too
high. Measure servo motor
ambient temperature. Reduce ambient tempera-
ture to below 40ºC.
Servo motor surface dirty. Visual check Clean dust and oil from
motor surface.
Overloaded. Run under no load. Reduce load or replace
with larger capacity servo
motor.
Abnormal noise. Machine mounting
incorrectly. Servo motor mounting
screws loose? Tighten mounting screws.
Coupling not centered? Center coupling.
Coupling unbalanced? Balance coupling.
Bearing defective. Check noise and vibration
near bearing Consult your Yaskawa rep-
resentative if defective.
Machine causing
vibration. Foreign object intrusion,
damage or deformation of
sliding parts of the
machine. Consult with machine
manufacturer.
Speed reference 0V
but servomotor
rotates. Speed reference voltage
offset applied. — Adjust the reference offset.
Refer to sections 7.2.4 and
7.2.5 .
Symptom Cause Inspection Remedy