YASKAWA JUSP-MD D01A Series User Manual page 301

9 Troubleshooting
9.1.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
A.520:
Vibration Alarm
A.710:
A.720:
Overload
A.710: High Load
A.720: Low Load
A.730:
A.731:
Dynamic Brake
Overload
(An excessive power
consumption of dynamic
brake was detected.)
A.740:
Overload of Surge
Current Limit Resistor
(The main circuit power
is turned ON/OFF too
frequently.)
9-12
Cause
Abnormal vibration was detected
at the motor speed.
The moment of inertia ratio
(Pn103) value is greater than the
actual value or is greatly
changed.
Incorrect wiring or contact fault
of servomotor and encoder.
Operation beyond the overload
protection characteristics.
Excessive load was applied
during operation because the ser-
vomotor was not driven due to
mechanical problems.
A fault occurred in the SERVO-
PACK or converter.
The servomotor rotates because
of external force.
The rotating energy at a DB stop
exceeds the DB resistance capac-
ity.
The setting of Pn001.0 (Servo-
motor Power OFF or Alarm Gr.1
Stop Mode) is not correct.
The setting of Pn601 does not
agree with the dynamic brake
resistance that is connected.
The connection of the dynamic
brake unit is faulty.
A fault occurred in the SERVO-
PACK.
The inrush current limit resistor
operation frequency at the main
circuit power supply ON/OFF
operation exceeds the allowable
range.
A fault occurred in the SERVO-
PACK or converter.
Investigative Actions
Check for abnormal noise from the
servomotor, and check the speed
and torque waveforms during oper-
ation.
Check the moment of inertia ratio.
Check the wiring.
Check the servomotor overload
characteristics and executed run
command.
Check the executed operation refer-
ence and motor speed.
−
Check the operation status.
Check the power consumed by DB
resistance (Un00B) to see how
many times the DB has been used.
Check the setting of Pn001.0.
Check the setting of Pn601.
Check the wiring between the
dynamic brake unit and DU, DV,
DW, and CN115 is correct and
securely connected.
−
−
−
(cont'd)
Corrective Actions
Reduce the motor speed or reduce
the speed loop gain (Pn100).
Set the moment of inertia ratio
(Pn103) to an appropriate value.
Confirm that the servomotor and
encoder are correctly wired.
Reconsider the load conditions and
operating conditions. Or, increase
the motor capacity.
Remove the mechanical problems.
The SERVOPACK or converter
may be faulty. Replace the SERVO-
PACK or converter.
Take measures to ensure the servo-
motor will not rotate because of
external force.
Reconsider the following:
• Reduce the motor reference
speed.
• Reduce the moment of inertia
ratio.
• Reduce the number of times of
the DB stop operation.
To not use the dynamic brake, set
Pn001.0 to 2. (The dynamic brake
will not be used and the motor will
coast to a stop.)
Set Pn601 correctly.
Correctly wire and securely connect
the dynamic brake unit with DU,
DV, DW, and CN115.
The SERVOPACK may be faulty.
Replace the SERVOPACK.
Reduce the frequency of turning the
main circuit power supply ON/OFF.
The SERVOPACK or converter
may be faulty. Replace the SERVO-
PACK or converter.