Yaskawa F7 Drive User Manual - Manual (Page 134)

Diagnostics & Troubleshooting 6 - 9
Table 6.1 Fault Displays and Processing (continued)
Digital
Operator Display
Description Cause Corrective Action
SER
Search Retry Err
<3021>
Exceeded Allowable Number of Speed
Search Retries
The speed search has been retried more than
the number of tries set in b3-19 (Number of
speed search retrials).
The settings in b3-17 and
b3-18 are not appropriate. Make sure that the settings in
b3-17 and b3-18 are appropriate.
SVE
Zero Servo Fault
Zero Servo Fault
The motor position moved more than
10,000 revolutions during zero servo
operation.
The torque limit was too small. Increase the torque limit.
The load torque was too large. Reduce the load torque.
Control circuit fault Check for signal noise.
UL3
Undertorq Det 1
Undertorque Detection 1
Drive output current < L6-02 for more than
the time set in L6-03 when L6-01 = 7 or 8.
Motor was underloaded.
Ensure the values in L6-02 and
L6-03 are appropriate.
Check application/machine status
to eliminate fault.
UL4
Undertorq Det 2
Undertorque Detection 2
Drive output current < L6-05 for more than
the time set in L6-06 when L6-04 = 7 or 8.
Motor was underloaded.
Ensure the values in L6-05 and
L6-06 are appropriate.
Check application/machine status
to eliminate fault.
UV1
DC Bus Undervolt
DC Bus Undervoltage
208-240Vac: Default trip point is
≤ 190Vdc
480Vac: Default trip point is
≤ 380Vdc
Trip point is adjustable in L2-05.
Detected when the DC bus voltage is
≤ L2-05.
Low input voltage at R/L1,
S/L2 and T/L3.
Check the input circuit and
increase the input power to within
specifications.
The acceleration time is set too
short.
Extend the time in C1-01 or other
active accel settings used such as
C1-03, C1-05, or C1-07 (time).
Voltage fluctuation of the input
power is too large.
Check the input voltage.
UV2
CTL PS Undervolt
Control Power Supply Undervoltage
Undervoltage of the control circuit when
running.
External load was
pulling down the Drive’s
power supplies, or there was
an internal short in the power/
gate Drive board.
Cycle power to the Drive.
Remove all control wiring and test
Drive or disconnect control
terminal strip.
Repair or replace the Power PCB/
Gate Drive PCB.
UV3
MC Answerback
Soft Charge Circuit Fault
The pre-charge contactor opened while the
Drive was running.
Contacts on the soft charge
contactor were dirty and the
soft charge contactor does not
function mechanically.
Cycle power to the Drive.
Check the condition of the soft
charge contactor.
Repair or replace the Power PCB/
Gate Drive PCB.