YASKAWA GA800 Maintenance & Troubleshooting page 108

2.4 Fault
Code Name
Note:
• The drive detects this fault if the motor speed is more than the value set in F1-08 for longer than F1-09.
• Do a Fault Reset to clear the fault.
• If the drive detects this fault, it will operate the motor as specified by the Stopping Method set in F1-03 [Overspeed Detection Selection].
Code Name
ov Overvoltage
108
Causes
If the drive detects the fault at start or in the low
speed range (10% or less) and n8-57 = 1 [HFI
Overlap Selection = Enabled] for PM Control
methods, the high frequency injection gain is too
high.
Causes
The deceleration time is too short and too much
regenerative energy is flowing back into the drive.
The acceleration time is too short.
The braking load is too large.
There are surge voltages in the input power supply.
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).
The speed search-related parameters are set
incorrectly (this fault also occurs during recovery
from momentary power loss and after Auto Restarts).
The power supply voltage is too high.
The braking resistor or braking resistor unit wiring is
incorrect.
The encoder cable is disconnected or wired
incorrectly.
Noise interference along the encoder cable.
Electrical interference caused a drive malfunction.
The load inertia is set incorrectly.
The Short Circuit Braking function used in OLV/PM
control method.
There is motor hunting.
YASKAWA TOEPYAIGA8001B GA800 Drive Maintenance & Troubleshooting
Possible Solutions
• Set E5-xx [PM Motor Parameters] correctly or do Rotational
Auto-Tuning.
• Decrease the value of n8-41 [HFI P Gain] in 0.5 unit increments.
Note:
Set n8-41 > 0.0 for IPM motors.
Possible Solutions
• Set L3-04 = 1 [Stall Prevention during Decel = General
Purpose].
• 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.
• 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].
Connect a dynamic braking option to the drive.
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.
1. Examine the motor main circuit cable, terminals, and motor
terminal box, and then remove ground faults.
2. Re-energize the drive.
• 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 set
b3-24 = 1 [Speed Search Method Selection = Speed Estimation].
Decrease the power supply voltage to match the drive rated voltage.
Correct wiring errors in the connection to the braking resistor or
braking resistor unit.
Examine for wiring errors or disconnected wires in the encoder
cable, and repair problems.
Isolate the encoder cable from the drive output line or a different
source of electrical interference.
• 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.
• 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.
Connect a braking resistor to the drive.
• Adjust n1-02 [Hunting Prevention Gain Setting].
• Adjust n2-02 [Automatic Freq Regulator Time 1] and n2-03
[Automatic Freq Regulator Time 2].
• Adjust n8-45 [Speed Feedback Detection Gain] and n8-47 [Pull-
in Current Comp Filter Time].