YASKAWA GA800 Technical Reference page 398

7.5 Minor Faults/Alarms
Code Name
ov Overvoltage
Note:
• The drive detects this error if the DC bus voltage is more than the ov detection level when there is no Run command (while the drive is stopped).
• The ov detection level is approximately 410 V with 200 V class drives. The detection level is approximately 820 V for 400 V class drives.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will activate.
Code Name
ovEr Too Many Parameters Changed
Code Name
PASS Modbus Communication Test
Code Name
PF Input Phase Loss
Note:
• The drive detects this error if the DC bus voltage changes irregularly without regeneration.
• If the drive detects this error, the terminal assigned to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will be ON.
• Use L8-05 [Input Phase Loss Protection Sel] to enable and disable PF detection.
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Causes
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 power supply voltage is too high.
Electrical interference caused a drive malfunction.
The drive detects ov [Overvoltage] when:
• The acceleration completes
• The deceleration starts
• The load changes suddenly
Causes
You tried to change more than 150 parameters.
Causes
The MEMOBUS/Modbus communications test is
complete.
Causes
There is a phase loss in the drive input power.
Loose wiring in the input power terminals.
The drive input power voltage is changing too much.
Unsatisfactory balance between voltage phases.
The main circuit capacitors have become
unserviceable.
Possible Solutions
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.
Decrease the power supply voltage to match the drive rated voltage.
• 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.
• Set L5-01 ≠ 0 [Number of Auto-Restart Attempts ≠ 0 times].
• Increase the value set in n2-03 [Automatic Freq Regulator Time
2] in 50 ms increments.
Note:
Make sure that you set n2-02 ≤ n2-03. When you adjust n2-03,
you must also increase the C4-06 [Motor 2 Torque Comp Delay
Time] value by same ratio.
• Increase C4-06 in 10 ms increments.
Note:
Make sure that you set C4-02 ≤ C4-06. When you adjust C4-06,
you must also increase the n2-03 value by same ratio.
Possible Solutions
Make sure that parameters that do not have an effect on drive
operation are at their default settings.
Note:
• You can change 150 parameters maximum.
• If you change parameters that have dependencies, the drive
can detect ovEr when the number of changed parameters is
fewer than 150.
Possible Solutions
The PASS display will turn off after communications test mode is
cleared.
Possible Solutions
Correct all wiring errors with the main circuit power supply.
Tighten the screws to the correct tightening torque.
• Examine the supply voltage for problems.
• Make the drive input power stable.
• Examine the supply voltage for problems.
• Make the drive input power stable.
• If the supply voltage is good, examine the magnetic contactor on
the main circuit side for problems.
• Examine the capacitor maintenance time in monitor U4-05
[CapacitorMaintenance].
• If U4-05 is more than 90%, replace the capacitor. Contact
Yaskawa or your nearest sales representative for more
information.
• Examine the supply voltage for problems.
• Re-energize the drive.
• If the alarm stays, replace the circuit board or the drive. Contact
Yaskawa or your nearest sales representative for more
information.
YASKAWA SIEPC71061737D GA800 Drive Technical Reference