9 - 4
9. TROUBLESHOOTING
9.1.2
Speed control mode
No.
Start-Up Sequence
Fault
Investigation
Possible Cause
Refer To
Not improved if connectors
CN1A, CN1B and CNP2 are
disconnected.
1. Power supply voltage fault
2. Servo amplifier is faulty.
Improved when connectors
CN1A and CN1B are
disconnected.
Power supply of CN1 cabling is
shorted.
x
LED is not lit.
x
LED flickers.
Improved when connector
CNP2 is disconnected.
1. Power supply of encoder
cabling is shorted.
2. Encoder is faulty.
1
Power on
Alarm occurs.
Refer to Section 9.2 and remove cause.
Section 9.2
Alarm occurs.
Refer to Section 9.2 and remove cause.
Section 9.2
2
Switch on servo-on
signal.
Servo motor shaft is
not servo-locked
(is free).
Check the display to see if
the servo amplifier is ready
to operate.
1. Servo on signal is not input.
(Wiring mistake)
2. 24VDC power is not
supplied to COM.
Section 6.3
Call the status display and
check the input voltage of
the analog speed command.
Analog speed command is 0V.
Section 6.2
Call the external I/O signal
display and check the
ON/OFF status of the input
signal.
LSP, LSN, ST1 or ST2 is off.
Section 6.6
Check the internal speed
commands 1 to 3
(parameters No. 8 to 10).
Set value is 0.
3
Switch on forward
rotation start (ST1)
or reverse rotation
start (ST2).
Servo motor does
not rotate.
Check the internal torque
limit 1 (parameter No. 28).
Set value is 0.
(1), Section
5.1.2
Gain adjustment
Rotation ripples
(speed fluctuations)
are large at low
speed.
Make gain adjustment in the
following procedure:
1. Increase the auto tuning
response level.
2. Repeat acceleration and
deceleration several
times to complete auto
tuning.
Gain adjustment fault
Chapter 7
4
Large load inertia
moment causes the
servo motor shaft to
oscillate side to side.
Make gain adjustment in the
following procedure:
If the servo motor may be
run with safety, repeat
acceleration and
deceleration several times
to complete auto tuning.
Gain adjustment fault
Chapter 7
