Yaskawa Sigma II Series SGMVH - Manual (Page 298)

10.1 Troubleshooting
10-17
10
Inspection, Maintenance, and
T
roubleshooting
Abnormal
Noise from
Servomotor Mounting not secured Check if there are any loosen mounting
screws. Tighten the mounting screws.
Check if there are misalignment of cou-
plings. Align the couplings.
Check if there are unbalanced couplings. Balance the couplings.
Defective bearings Check for noise and vibration around the
bearings. If any problems, contact your Yaskawa representative.
Vibration source on the driven
machine Any foreign matter, damages, or deforma-
tion on the machine movable section. Contact the machine manufacturer.
Noise interference due to incorrect
input signal wire specifications Check if the cable meets the recommended
specification. Use the specified input signal wires.
Noise interference due to long dis-
tance of input signal line The wiring distance must be 3 m max. and
the impedance a few hundreds ohm max. Shorten the wiring distance for input signal line to the
specified value.
Noise interference due to incorrect
encoder cable specifications Check if the cable meets the recommended
specification. Use the specified encoder cable.
Noise interference due to long
encoder cable wiring distance The wiring distance must be 20 m max. Shorten the encoder cable wiring distance to the speci-
fied value.
Noise due to damaged encoder cable Check if the encoder cable is not damaged
or bent. Modify the encoder cable layout.
Excessive noise to the encoder cable Check if the encoder cable is bundled with
high-current line. Install a surge suppressor to the encoder cable.
FG electrical potential varies by
influence of such machines on the
servomotor side as welders. Check if the machine is correctly grounded. Ground the machine separately from PG side FG.
SERVOPACK pulse counting error
due to noise Check if there is noise interference on the
signal line from encoder. Take measure against noise for the encoder wiring.
Encoder fault − Replace the servomotor.
Servomotor
Vibrates at
about 200 to
400 Hz Speed loop gain value (Pn100) too
high. Factory setting: Kv=40.0 Hz * Reduce speed loop gain (Pn100) preset value.
Position loop gain value (Pn102) too
high Factory setting: Kp=40.0/s * Reduce position loop gain (Pn102) preset value.
Incorrect speed loop integral time
constant (Pn101) setting Factory setting: Ti=20.00 ms * Correct the speed loop integral time constant (Pn101)
setting.
When the autotuning is not used:
Incorrect rotational moment of iner-
tia ratio data − Correct the rotational moment of inertia ratio data
(Pn103).
High
Rotation
Speed
Overshoot on
Starting and
Stopping. Speed loop gain value (Pn100) too
high
Factory setting: Kv=40.0 Hz * Reduce the speed loop gain (Pn100) preset value.
Position loop gain value (Pn102) too
high Factory setting: Kp=40.0/s * Reduce the position loop gain (Pn102) preset value.
Incorrect speed loop integral time
constant (Pn101) setting Factory setting: Ti=20.00 ms * Correct the speed loop integral time constant (Pn101)
setting.
Incorrect moment of inertia ratio
(Pn103) setting − Correct the rotational moment of inertia ratio data
(Pn103).
* Refer to 9.3.2 Servo Gain Manual Tuning.
Table 10.7 Troubleshooting for Malfunction without Alarm Display (cont’d)
Symptom Cause
Inspection Corrective Actions
: Turn OFF the servo system before executing operations.