Instruction manual

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4. STARTUP
4.3.6 Trouble at start-up
CAUTION
Excessive adjustment or change of parameter setting must not be made as it will
make operation instable.
POINT
Using the optional servo configuration software, you can refer to unrotated
servo motor reasons, etc.
The following faults may occur at start-up. If any of such faults occurs, take the corresponding action.
No. Start-up sequence Fault Investigation Possible cause Reference
Not improved if connectors CN1, CN2
and CN3 are disconnected.
1. Power supply voltage fault
2. Servo amplifier is faulty.
Improved when connectors CN1 is
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.
LED is not lit.
LED flickers.
Improved when connector CN3 is
disconnected.
Power supply of CN3 cabling is
shorted.
1 Power on
Alarm occurs. Refer to Chapter 9 and remove cause. Chapter 9
Alarm occurs. Refer to Chapter 9 and remove cause. Chapter 92 Switch on servo-
on (SON).
Servo motor shaft is
not servo-locked
(is free).
1. Check the display to see if the
servo amplifier is ready to operate.
2. Check the external I/O signal
indication (Section 6.7) to see if the
servo-on (SON) is ON.
1. Servo-on (SON) is not input.
(Wiring mistake)
2. External 24VDC power is not
supplied to DICOM.
Section 6.7
Call the status display and check the
input voltage of the analog speed
command (VC).
Analog speed command is 0V. Section 6.3
Call the external I/O signal display
(Section 6.3) 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 7
(parameters No. PC05 to PC11).
Set value is 0.
Check the forward torque limit
(Parameter no. PA11) or reverse
torque limit (Parameter no. PA12)
Torque limit level is too low as
compared to the load torque.
3 Switch on forward
rotation start
(ST1) or reverse
rotation start
(ST2).
Servo motor does
not rotate.
When the analog torque limit (TLA) is
usable, check the input voltage on the
status display.
Torque limit level is too low as
compared to the load torque.
Section
5.1.9
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 Gain adjustment
Large load inertia
moment causes the
servo motor shaft to
oscillate side to side.
If the servo motor may be run with
safety, repeat acceleration and
deceleration several times to
complete auto tuning.
Gain adjustment fault Chapter 7