YASKAWA FSDrive-MV1000 Series Instructions For Use Manual page 169

Digital Operator Display
Uv
Cause
Phase loss in the drive input power
Loose wiring in the drive input power terminals
There is a problem with the drive input power
voltage.
The power has been interrupted.
Digital Operator Display
VUB
Cause
The motor has been damaged due to
overheating or the motor insulation is damaged.
One of the motor cables has shorted out or there
is a grounding problem.
The output side cable wiring is wrong.
YASKAWA ELECTRIC TOEP C710687 02B FSDrive-MV1000 Instructions
Undervoltage
One of the following conditions occurred while the drive was stopped (a Run command was not
entered):
• DC bus voltage dropped below the level specified in L2-05.
• Contactor to suppress inrush current in the drive was opened.
• Low voltage in the control drive input power.
Possible Solutions
Check for wiring errors in the main circuit drive input power. Correct the
wiring.
Retighten the terminals to the tightening torques specified in this manual.
Refer to Wire Gauges and Tightening Torques on page 91
Lower the voltage of the drive input power so it is within the limits listed
in the specifications.
Correct the drive input power.
Voltage Unbalance
The sum of the detected output voltages of the three phases exceeded the detection level for
longer than the stipulated time.
Possible Solutions
Check the insulation resistance of the motor. Replace the motor.
Check the motor cable. Remove the short circuit and reapply power.
Check the resistance between the motor cables and ground terminal
Replace the cable.
Correct the wiring.
5.5 Alarm Detection
Minor Fault Name
for details.
Minor Fault Name
Minor Fault Output
H2- =10
Yes
Minor Fault Output
H2- =10
Yes
.
5
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