YASKAWA SGDV-OCA05A - Page 466

14.2 Alarm Displays
14.2.2 Troubleshooting Alarms
14
Maintenance
14-25
A.840:
Encoder Data
Alarm
(Detected at the
encoder.)
The encoder malfunc-
tioned.
–
Turn the power supply to
the SERVOPACK OFF and
ON again. If an alarm still
occurs, the Servomotor or
linear encoder may be
faulty. Replace the Servo-
motor or linear encoder.
–
An error occurred in
reading data from the
linear encoder.
–
The linear encoder is not
mounted within an appro-
priate tolerance. Correct
the mounting of the linear
encoder.
–
Excessive speed
occurred in the linear
encoder.
–
Control the motor speed
within the range specified
by the linear encoder
manufacturer and then
turn ON the control power
supply.
–
The encoder malfunc-
tioned due to noise.
–
Correct the wiring around
the encoder by separating
the Encoder Cable from
the Servomotor Main Cir-
cuit Cable or by ground-
ing the encoder.
–
The polarity sensor is
not wired correctly.
Check the wiring of the
polarity sensor.
Correct the wiring of the
polarity sensor.
–
The polarity sensor
failed.
–
Replace the polarity sen-
sor.
–
A.850:
Encoder Over-
speed
(Detected when a
Rotary Servomo-
tor, Absolute Lin-
ear Encoder, or
Direct Drive Ser-
vomotor is con-
nected. However,
SGMCS Incre-
mental Encoder
specifications are
excluded.)
(Detected at the
encoder end.)
Rotary Servomotor:
The Servomotor
speed was 200 min
-1
or higher when the
control power supply
was turned ON.
Check the motor speed
when the power supply
is turned ON.
Reduce the Servomotor
speed to a value less than
200 min
-1
, and turn ON
the control power supply.
–
Linear Servomotor:
The Servomotor
exceeded the speci-
fied speed when the
control power supply
was turned ON.
Check the motor speed
when the power supply
is turned ON.
Control the motor speed
within the range specified
by the linear encoder
manufacturer and then
turn ON the control power
supply.
–
A failure occurred in
the encoder.
–
Turn the power supply to
the SERVOPACK OFF and
ON again. If an alarm still
occurs, the Servomotor or
linear encoder may be
faulty. Replace the Servo-
motor or linear encoder.
–
A failure occurred in
the SERVOPACK.
–
Turn the power supply to
the SERVOPACK OFF and
ON again. If an alarm still
occurs, the SERVOPACK
may be faulty. Replace the
SERVOPACK.
–
Continued on next page.
Continued from previous page.
Alarm Number:
Alarm Name
Possible Cause Confirmation Correction Reference