YASKAWA SGD7S Product Manual page 431

Alarm Number:
Possible Cause
Alarm Name
The encoder malfunc-
tioned.
An error occurred in
reading data from the
linear encoder.
A.840:
Encoder Data
Excessive speed
Alarm
occurred in the linear
(Detected at the
encoder.
encoder.)
The encoder malfunc-
tioned due to noise.
The polarity sensor is
not wired correctly.
The polarity sensor
failed.
Rotary Servomotor:
The Servomotor
speed was 200 min
or higher when the
control power supply
was turned ON.
Linear Servomotor:
The Servomotor
exceeded the speci-
A.850:
fied speed when the
Encoder Over-
control power supply
speed
was turned ON.
(Detected at the
encoder when
the control power
supply is turned
A failure occurred in
ON.)
the encoder.
A failure occurred in
the SERVOPACK.
Confirmation
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Check the wiring of the
polarity sensor.
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Check the motor speed
-1
when the power supply
is turned ON.
Check the motor speed
when the power supply
is turned ON.
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12.2 Alarm Displays
12.2.2 Troubleshooting Alarms
Continued from previous page.
Correction
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.
The linear encoder is not
mounted within an appro-
priate tolerance. Correct
the mounting of the linear
encoder.
Control the motor speed
within the range specified
by the linear encoder
manufacturer and then
turn ON the control power
supply.
Correct the wiring around
the encoder by separating
the Encoder Cable from
the Servomotor Main Cir-
cuit Cable or by ground-
ing the encoder.
Correct the wiring of the
polarity sensor.
Replace the polarity sen-
sor.
Reduce the Servomotor
speed to a value less than
-1
200 min , and turn ON
the control power supply.
Control the motor speed
within the range specified
by the linear encoder
manufacturer and then
turn ON the control power
supply.
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.
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.
Reference
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12
12-25