YASKAWA UAK series User Manual

11 Inspection, Maintenance, and Troubleshooting
11.3.2 Troubleshooting of Warnings
11-38
A.91A:
Converter
Electric
Operation
Overload
The sequence of phase
U, V, and W motor lines
is incorrect.
Check the wiring of the motor’s main
circuit cable.
Correct the motor wiring.
The motor main circuit
cable is either incor-
rectly wired or has a
contact fault.
Make sure the wiring is correct. Correct the wiring.
A mistake occurred
when selecting the
power regeneration con-
verter capacity.
Check the power regeneration con-
verter capacity and the total output
capacity of the SERVOPACK.
Change the power regeneration con-
verter capacity.
Converter current detec-
tion circuit failure
−
Turn the power supply OFF and then
ON again. If the warning still occurs,
the power regeneration converter may
be faulty. Replace the power regenera-
tion converter.
The AC power supply
voltage is low.
Measure the power supply voltage.
Set AC power supply voltage within
the specified range.
A.91B:
Converter Power
Supply
Regenerative
Overload
A mistake occurred
when selecting the
power regeneration con-
verter capacity.
Check the power regeneration con-
verter capacity and the total output
capacity of the SERVOPACK.
Change the power regeneration con-
verter capacity.
The AC power supply
voltage is low.
Measure the power supply voltage.
Set AC power supply voltage within
the specified range.
Power regeneration
converter failure
−
Turn the power supply OFF and then
ON again. If the warning still occurs,
the power regeneration converter may
be faulty. Replace the power regenera-
tion converter.
A.921:
Dynamic Brake
Overload
(Warning before
the alarm A.731
occurs)
The servomotor rotates
because of external
force.
Check the operation status.
Take measures to ensure the servomo-
tor will not rotate because of external
force.
The rotating energy at a
DB stop exceeds the DB
resistance capacity.
Check the power consumed by DB
resistance monitor in SigmaWin for Σ-
V-S D (MT) to see how many time s t h e
DB has been used.
Reconsider the following:
•Reduce the servomotor reference
speed.
•Reduce the moment of inertia ratio.
•Reduce the number of times of the
DB stop operation.
SERVOPACK failure −
The SERVOPACK may be faulty.
Replace the SERVOPACK.
A.923:
Built-in Fan in
SERVOPACK
Stopped
The fan inside the SER-
VOPACK stopped.
Check for foreign matter or debris
inside the SERVOPACK.
Remove foreign matter. If the warning
still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
A.92B:
Built-in Fan in
Converter
Stopped
The fan inside the
power regeneration con-
verter stopped.
Check for foreign matter or debris
inside the power regeneration con-
verter.
Remove the foreign matter. If the
warning still occurs, the power regen-
eration converter may be faulty.
Replace the power regeneration con-
verter.
(cont’d)
Warning
Number:
Warning Name
(Warning
Description)
Cause Investigative Actions Corrective Actions

YASKAWA UAK series Specifications

General

Brand	YASKAWA
Model	UAK series
Category	Servo Drives
Language	English