YASKAWA E7LVD002 Technical Manual page 184

Digital
Operator Display
Dynamic Braking Resistor
RH
The protection of the dynamic braking
DynBrk Resistor
resistor based on setting of L8-01
RR
Dynamic Braking Transistor
DynBrk Transistr
The dynamic braking transistor failed.
DC Bus Undervoltage
UV1
The DC bus voltage is ≤ L2-05
DC Bus Undervolt
208-240VAC: Trip point is ≤ 190Vdc
480VAC: Trip point is ≤ 380Vdc
Control Power Supply Undervoltage
UV2
Undervoltage of the control circuit when
CTL PS Undervolt
running.
Soft Charge Circuit Fault
UV3
The pre-charge contactor opened while the
MC Answerback
Drive was running.
Some features within the PI function group cause the Drive to shut down momentarily (e.g. Sleep Function,
Snooze Function, Feedback Loss feature etc.) Upon recovery from the conditions that activate these features,
WARNING
the Drive may start unexpectedly. Therefore, when enabling these features take appropriate measures to
notify personnel working with this equipment that unexpected starting may occur.
Table 6.3 Fault Displays and Processing (Continued)
Description
Diagnostic & Troubleshooting 6 - 12
Cause
Overhauling load, extended
dynamic braking duty cycle,
defective dynamic braking
resistor.
Shorted dynamic braking
transistor, high DC bus
voltage, defective dynamic
braking resistor.
Low input voltage at R/L1,
S/L2 and T/L3
The acceleration time is set too
short.
Voltage fluctuation of the input
power is too large.
External load connected
pulling down the Drive power
supplies.
Contacts on the soft charge
contactor are dirty and the soft
charge contactor does not
function mechanically.
Corrective Action
Verify dynamic braking duty
cycle.
Monitor DC bus voltage.
Replace dynamic braking
resistor.
Cycle power off and on to the
Drive.
Replace defective dynamic
braking transistor or resistor...
Monitor DC bus voltage.
Check the input circuit and
increase the input power to within
specifications.
Extend the time in C1-01.
Check the input voltage.
Cycle power off and on to the
Drive.
Repair or replace the Power PCB/
Gate Drive PCB.
Remove all control wiring and
test Drive.
Cycle power off and on to the
Drive.
Check the condition of the soft
charge contactor.
Repair or replace the Power PCB/
Gate Drive PCB.