Yaskawa E7B Drive Bypass - Manual (Page 189)

Diagnostic & Troubleshooting 6 - 9
PF
Input Pha Loss
Input Phase Loss
Drive input power supply has an open phase
or has a large imbalance of input voltage.
Open phase on the input of the
Drive.
Check the input voltage.
Loose terminal screws at
R/L1, S/L2 or T/L3.
Tighten the terminal screws.
Momentary power loss
occurred.
Check the input voltage.
Input voltage fluctuation too
large.
Check the input voltage.
Parameter L8-06 value is set
incorrectly.
Verify parameter L8-06 is set
correctly per the kVA tables on
pages B-4 and B-5. Adjust L8-06
according to your application.
The higher the value the less
sensitive it becomes.
CAUTION: Changing this
parameter from the factory
default setting may cause
Drive failure and void the
product warranty. (Consult
the factory for application
assistance).
PUF
DC Bus Fuse Open
DC Bus Fuse
Detects if the DC bus fuse has opened Shorted output transistor(s) or
terminals.
Remove power from the Drive.
Disconnect the motor.
Perform the checks without
power in Table 6.6.
Replace the shorted
component(s).
Replace the defective fuse.
RH
DynBrk Resistor
Dynamic Braking Resistor
The protection of the dynamic braking
resistor based on setting of L8-01
Overhauling load, extended
dynamic braking duty cycle,
defective dynamic braking
resistor.
Verify dynamic braking duty
cycle.
Monitor DC bus voltage.
Replace dynamic braking
resistor.
RR
DynBrk Transistr
Dynamic Braking Transistor
The dynamic braking transistor failed.
Shorted dynamic braking
transistor, high DC bus
voltage, defective dynamic
braking resistor.
Cycle power off and on to the
Drive.
Replace defective dynamic
braking transistor or resistor.
..
Monitor DC bus voltage.
Table 6.1 Fault Displays and Processing
Digital
Operator Display
Description Cause Corrective Action