YASKAWA Z1000 User Manual page 214

5.4 Fault Detection
Digital Operator Display
Cause
Parameter settings are not appropriate for the
load
There is a fault on the machine side
Digital Operator Display
UL6
Cause
The output current has fallen below the motor
underload curve defined in L6-14 for longer
than the time set to L6-03
Digital Operator Display
Cause
Input power phase loss
One of the drive input power wiring terminals
is loose
There is a problem with the voltage from the
drive input power
The power has been interrupted
The main circuit capacitors are worn
The relay or contactor on the soft-charge
bypass relay is damaged
Digital Operator Display
Cause
L2-02 was changed from its default value
without installing a Momentary Power Loss
Ride-Thru unit
Control power supply wiring is damaged
Internal circuitry is damaged
214
Undertorque Detection 1
UL3
The current has fallen below the minimum value set for Torque Detection Level 1 (L6-02) for longer than
the allowable time (L6-03).
Check the settings of parameters L6-02 and L6-03.
Check the load for any problems.
Motor Underload
UL6
The weight of the load has fallen below the underload curve defined in L6-14.
Adjust the value set to L6-14 so that output current remains above the motor underload curve during
normal operation.
DC Bus Undervoltage
One of the following conditions occurred while the drive was running:
• Voltage in the DC bus fell below the undervoltage detection level (L2-05).
Uv1
• For 600 V class drives: approximately 475 V
The fault is output only if L2-01 is set to 0 or 1 and the DC bus voltage has fallen below the level set to
L2-05 for longer than the time set to L2-02.
• The main circuit drive input power is wired incorrectly.
• Correct the wiring.
• Ensure there are no loose terminals.
• Apply the tightening torque specified in this manual to fasten the terminals.
Wire Gauges and Tightening Torque on page 81
• Check the voltage.
• Correct the voltage to be within the range listed in drive input power specifications.
• If there is no problem with the power supply to the main circuit, check for problems with the main
circuit magnetic contactor.
Correct the drive input power.
• Check the maintenance time for the capacitors (U4-05).
• Replace either the control board or the entire drive if U4-05 exceeds 90%. For instructions on replacing
the control board, contact Yaskawa or a Yaskawa representative.
• 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.
Control Power Supply Voltage Fault
Uv2
Voltage is too low for the control drive input power.
Correct the setting to L2-02 or install an optional Momentary Power Loss Ride-Thru unit.
• 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.
• 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.
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
for details.
Fault Name
Possible Solution
YASKAWA TOEP YAIZ1U 03B YASKAWA AC Drive – Z1000 User Manual
Refer to Main Circuit