YASKAWA GA50U Series

13 Troubleshooting
104 YASKAWA TOEPC71061752B GA500 Drive Installation & Primary Operation
Code Name Causes Possible Solutions
ov Overvoltage
The deceleration time is too short
and too much regenerative energy
is flowing back into the drive.
• Increase the values set in C1-02, C1-04,
C1-06, or C1-08 [Deceleration Times].
• Connect a dynamic braking option to the
drive.
• Perform Deceleration Rate Tuning.
The acceleration time is too short. • Make sure that sudden drive acceleration
does not cause the fault.
• Increase the values set in C1-01, C1-03,
C1-05, or C1-07 [Acceleration Times].
• Increase the value set in C2-02 [S-Curve
Time @ End of Accel].
• Set L3-11 = 1 [Overvoltage Suppression
Select = Enabled].
The braking load is too large. Connect a dynamic braking option to the
drive.
There are surge voltages in the
input power supply.
Connect a DC link choke to the drive.
Note:
If you turn the phase advancing
capacitors ON and OFF and use
thyristor converters in the same power
supply system, there can be surge
voltages that irregularly increase the
input voltage.
The drive output cable or motor is
shorted to ground (the current
short to ground is charging the
main circuit capacitor of the drive
through the power supply).
1. Examine the motor main circuit cable,
terminals, and motor terminal box, and
then remove ground faults.
2. Re-energize the drive.
The speed search-related
parameters are set incorrectly (this
fault also occurs during recovery
from momentary power loss and
after Auto Restarts).
• Examine the settings for all speed search
related parameters.
• Set b3-19 ≠ 0 [Speed Search Restart
Attempts ≠ 0 times].
• Adjust b3-03 [Speed Search
Deceleration Time].
• Do Stationary Auto-Tuning for Line-to-
Line Resistance and then set b3-24 = 1
[Speed Search Method Selection = Speed
Estimation].
The power supply voltage is too
high.
Decrease the power supply voltage to match
the drive rated voltage.
The braking resistor or braking
resistor unit wiring is incorrect.
Correct wiring errors in the connection to
the braking resistor or braking resistor unit.
Electrical interference caused a
drive malfunction.
• Examine the control circuit lines, main
circuit lines, and ground wiring, and
decrease the effects of electrical
interference.
• Make sure that a magnetic contactor is
not the source of the electrical
interference, then use a Surge Protective
Device if necessary.
The load inertia is set incorrectly. • Examine the load inertia settings with
KEB, overvoltage suppression, or stall
prevention during deceleration.
• Adjust L3-25 [Load Inertia Ratio] to
match the qualities of the machine.