Specifications

8. TROUBLESHOOTING
8– 4
8-1-2 Speed control mode
No. Start-Up Sequence Fault Investigation Possible Cause Refer To
1 Power on • LED is not lit.
• LED flickers.
Not improved if
connectors CN1A, CN1B
and CN2 are disconnected.
1) Power supply voltage
fault
2) Servo amplifier faulty.
Improved when
connectors CN1A and
CN1B are disconnected.
Power supply of CN1
cabling is shorted.
Improved when connector
CN2 is disconnected.
1) Power supply of
encoder cabling is
shorted.
2) Encoder is faulty.
Alarm occurs. Refer to Section 8-2 and remove cause.
Alarm occurs. Refer to Section 8-2 and remove cause.2 Switch on servo-on
signal.
Section 8-2
Section 8-2
Servo motor shaft is
free.
1. Check the display to see
if the servo amplifier is
ready to operate.
2. Check the external I/O
signal indication to see
if the servo-on (SON)
signal is ON.
(Wiring mistake)
2) 24VDC power is not
supplied to COM.
Servo motor does
not rotate.
Call the status display and
check the input voltage of
the analog speed command.
3 Switch on forward
rotation start (ST1)
or reverse rotation
start (ST2).
Section 2-3-2Analog speed command
is 0V.
(1), Section 2-3-3
Rotational 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.
4 Gain adjustment Section 2-4Gain adjustment fault
Large load inertia
moment causes the
servo motor 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.
Section 2-4Gain adjustment fault
Call the external I/O signal
display and check the ON/OFF
status of the input signal.
Check the internal speed
commands 1 to 3
(parameters No. 8 to 10).
LSP, LSN, ST1 or ST2 is
off.
Set value is 0.
Check the internal torque
limit 1 (parameter No. 28).
Set value is 0.
(1), Section 2-3-3
(3), Section 2-3-5