YASKAWA GA700 Technical Manual page 305

Code Name
oS Overspeed
Note:
• Detected if the motor speed exceeded the value set in F1-08 [Overspeed Detection Level] for longer than F1-09 [Overspeed Detection
Delay Time].
• If detected, H2-xx = 10 [MFDO Function Select = Minor Fault] will be ON.
• If detected, the drive will operate the motor according to the stop method set in F1-03 [Operation Select at Overspeed].
Code Name
ov Overvoltage
Note:
• Detected if the DC bus voltage exceeds the ov detection level when the Run command has not been input (while the drive is stopped).
• The ov detection level is about 410 V when using a 200 V class drive. For a 400 V class drive, the detection level is around 820 V.
• If detected, H2-xx = 10 [MFDO Function Select = Minor Fault] will be ON.
Code Name
PASS PASS
Code Name
PF Input Phase Loss
YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual
Cause
Overshoot is occurring.
Incorrect number of PG pulses has been
set.
The oS detection level has not been set
appropriately.
Cause
Surge voltages are entered into 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.
A drive malfunction occurred due to
noise.
Cause
The MEMOBUS/Modbus
communications test has finished
normally.
Cause
Phase loss in the drive input power.
Loose wiring in the input power
terminals.
Excessive fluctuation in the drive input
power voltage.
Poor balance between voltage phases.
6.5 Minor Faults/Alarms
Possible Solution
• Reduce C5-01 [ASR Proportional Gain 1] and
increase C5-02 [ASR Integral Time 1].
• Adjust the pulse train gain using the H6-02 to
H6-05 [Pulse Train Input Setting Parameters].
Set H6-02 [Pulse Train Input Scaling] to the pulse
train frequency during 100% reference (maximum
motor rotation speed).
Adjust F1-08 and F1-09.
Possible Solution
Connect a DC reactor to the drive.
Note:
Within the same power supply system, turning
phase advancing capacitors on and off,
operating thyristor converters, and the like may
apply surge voltages and cause the input voltage
to rise abnormally.
1. Check the motor main circuit cable, terminals,
and motor terminal box, and eliminate any
ground faults.
2. Restart the drive.
Lower the power supply voltage so that it matches
the drive rated voltage.
• Check the control circuit lines, main circuit
lines, and ground wiring, and minimize the
effects of noise.
• Check whether an electromagnetic contactor is
the noise source, and use Surge Protective
Device if necessary.
• Set L5-01 ≠ 0 [Number of Auto Restart Attempts
≠ 0 times].
Possible Solution
PASS display will disappear when communications
test mode is cleared.
Possible Solution
Correct any wiring errors in the main circuit drive
input power.
Properly tighten the terminals according to the
specified tightening torque.
Check the voltage from the drive input power and
review the possible solutions for stabilizing the
drive input power.
• Check the voltage from the drive input power
and review the possible solutions for stabilizing
the drive input power.
• Disable input phase loss detection.
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