The relay or contactor on the soft-charge
bypass circuit is damaged
• Cycle power to the drive and see if the fault reoccurs.
• If the problem continues, replace either the control board or the entire drive. For instructions on
replacing the control board, contact Yaskawa or a Yaskawa representative.
• Check monitor U4-06 for the performance life of the soft-charge bypass.
• Replace either the control board or the entire drive if U4-06 exceeds 90%. For instructions on replacing
the control board, contact Yaskawa or a Yaskawa representative.
Digital Operator Display
Fault Name
Uv2
Control Power Supply Voltage Fault
Voltage is too low for the control drive input power.
Cause
Possible Solution
In drive models 2A0004 to 2A0056 or 4A0002
to 4A0031, L2-02 was changed from its
default value without installing a Momentary
Power Loss Ride-Thru unit
Correct the setting to L2-02 or install an optional Momentary Power Loss Ride-Thru unit.
Control power supply wiring is damaged
• Cycle power to the drive. Check if the fault reoccurs.
• If the problem continues, replace the control board, the entire drive, or the control power supply. For
instructions on replacing the control board, contact Yaskawa or a Yaskawa representative.
Internal circuitry is damaged
• Cycle power to the drive. Check if the fault reoccurs.
• If the problem continues, replace either the control board or the entire drive. For instructions on
replacing the control board, contact Yaskawa or a Yaskawa representative.
Digital Operator Display
Fault Name
Uv3
Undervoltage 3 (Soft-Charge Bypass Relay Fault)
The soft-charge bypass relay failed.
Cause
Possible Solution
The relay or contactor on the soft-charge
bypass relay is damaged
• Cycle power to the drive and see if the fault reoccurs.
• Check monitor U4-06 for the performance life of the soft-charge bypass relay.
• Replace either the control board or the entire drive if U4-06 exceeds 90%. For instructions on replacing
the control board, contact Yaskawa or a Yaskawa representative.
Digital Operator Display
Fault Name
Uv4
Gate Drive Board Undervoltage
Voltage drop in the gate drive board circuit
Cause
Possible Solution
Not enough power is being supplied to the gate
drive board.
• Cycle power to the drive and see if the fault reoccurs.
Refer to Diagnosing and Resetting Faults on
• If the problem continues, replace either the gate drive board or the entire drive. For instructions on
replacing the gate drive board, contact Yaskawa or a Yaskawa representative.
<1> Detected in models 4A0930 and 4A1200.
Digital Operator Display
Fault Name
Uv5
MC/FAN power malfunction
Internal drive module MC / FAN power supply does not function properly.
Cause
Possible Solution
Internal drive module MC / FAN power
supply is low.
• Power the drive ON/OFF to verify operation.
• Refer to the manual section on how to restart the drive after an error.
• If the error occurs again replace the defective module or defective circuit board..
Digital Operator Display
Fault Name
voF
Output Voltage Detection Fault
Problem detected with the voltage on the output side of the drive.
Cause
Possible Solution
2.4 Fault Detection
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
201
2
Troubleshooting
Summary of Contents for A1000 HHP
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