YASKAWA CIPR-GA50UВ001AJ Series Installation & Primary Operation page 140

15 Troubleshooting
Code Name
Undertorque
UL4
Detection 2
Mechanical
UL5
Weakening Detection
2
Uv1 DC Bus Undervoltage
Control Power
Uv2
Undervoltage
140
Causes
A fault occurred on the
machine.
Example: There is a broken
pulley belt.
The parameters are incorrect for
the load.
The drive detected undertorque
as specified by the conditions
for mechanical weakening
detection set in L6-08
[Mechanical Fatigue Detect
Select].
There is a phase loss in the drive
input power.
There is loose wiring in the
drive input power terminals.
The drive input power voltage is
changing too much.
There was a loss of power.
The main circuit capacitors have
become unserviceable.
The relay or contactor on the
soft-charge bypass relay is
damaged.
The value set in L2-02 [Power
Loss Ride Through Time]
increased and the momentary
power loss recovery unit is not
connected to the drive.
YASKAWA TOEPC7106170YB YASKAWA AC Drive GA500 Installation & Primary Operation
Possible Solutions
Examine the machine and remove the
cause of the fault.
Adjust L6-05 [Torque Detection Level 2]
and L6-06 [Torque Detection Time 2]
settings.
Examine the machine for deterioration.
Correct errors with the wiring for main
circuit drive input power.
Tighten the terminal screws to the correct
tightening torque.
• Examine the input power for
problems.
• Make the drive input power stable.
• If the input power supply is good,
examine the magnetic contactor on
the main circuit side for problems.
Use a better power supply.
Examine the capacitor maintenance time
in monitor U4-05
[CapacitorMaintenance]. If U4-05 is
more than 90%, replace the control board
or the drive. For information about
replacing the control board, contact
Yaskawa or your nearest sales
representative.
U4-06 [PreChargeRelayMainte] shows
the performance life of the soft-charge
bypass relay. If U4-06 is more than 90%,
replace the board or the drive. For
information about replacing the board,
contact Yaskawa or your nearest sales
representative.
Connect the momentary power loss
recovery unit to the drive.