YASKAWA UAK series User Manual page 275

Alarm:
Alarm Name
Incorrect wiring or contact fault
of servomotor and encoder.
Operation beyond the overload
A.710:
protection characteristics.
A.720:
Overload
Excessive load was applied dur-
A.710: High Load
ing operation because the servo-
A.720: Low Load
motor was not driven due to
mechanical problems.
SERVOPACK failure
The sequence of phase U, V, and
W motor lines is incorrect.
The motor main circuit cable is
either incorrectly wired or has a
A.72A:
contact fault.
Converter Electric
A mistake occurred when select-
Operation Overload
ing the power regeneration con-
(A continuous operation
verter capacity.
drew power at a rate that
exceeded the rated out-
put of the power regen-
Converter current detection cir-
eration converter.)
cuit failure
The AC power supply voltage is
low.
A mistake occurred when select-
ing the power regeneration con-
A.72B:
verter capacity.
Converter Power
Supply Regenerative The AC power supply voltage is
Overload low.
(Continuous power
regeneration exceeded
Power regeneration converter
the ratings of the power
failure
regeneration converter.)
The servomotor rotates because
of external force.
A.730:
A.731:
Dynamic Brake
The rotating energy at a DB stop
Overload
exceeds the DB resistance capac-
(An excessive power
ity.
consumption of dynamic
brake was detected.)
SERVOPACK failure
The main circuit power supply
turned ON and OFF frequently.
A.74A:
Converter Inrush
Resistance Overload
(The main circuit power
supply turned ON and
Inrush limit circuit failure
OFF frequently.)
Cause Investigative Actions
Check the wiring.
Check the servomotor overload
characteristics and command.
Check the command and servomo-
tor speed.
−
Check the wiring of the motor's
main circuit cable.
Make sure the wiring is correct.
Check the power regeneration con-
verter capacity and the total output
capacity of the SERVOPACK.
−
Measure the power supply voltage.
Check the power regeneration con-
verter capacity and the total output
capacity of the SERVOPACK.
Measure the power supply voltage.
−
Check the operation status.
Check the DB resistor power con-
sumption monitor in SigmaWin for
the Σ-V-SD (MT) to see how many
times the DB has been used.
−
Check the ON/OFF sequence of the
main circuit power supply.
−
11.2 Alarm Displays
(cont'd)
Corrective Actions
Confirm that the servomotor and
encoder are correctly wired.
Reconsider the load conditions and
operation conditions. Or, increase
the servomotor capacity.
Remove the mechanical problems.
The SERVOPACK may be faulty.
Replace the SERVOPACK.
Correct the motor wiring.
Correct the wiring.
Change the power regeneration con-
verter capacity.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the power regeneration con-
verter may be faulty. Replace the
power regeneration converter.
Set AC power supply voltage within
the specified range.
Change the power regeneration con-
verter capacity.
Set AC power supply voltage within
the specified range.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the power regeneration con-
verter may be faulty. Replace the
power regeneration converter.
Take measures to ensure the servo-
motor will not rotate because of
external force.
• Reduce the servomotor reference
speed.
• Reduce the moment of inertia
ratio.
• Reduce the number of times of
the DB stop operation.
The SERVOPACK may be faulty.
Replace the SERVOPACK.
Change the sequence and operation
pattern such that the main circuit
power supply does not turn ON and
OFF frequently.
Turn the power supply OFF and
then ON again after cooling the
power regeneration converter to the
ambient temperature. If the alarm
still occurs, the power regeneration
converter may be faulty. Replace
the power regeneration converter.
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