Yaskawa E7 Drive User Manual - Manual (Page 143)

Diagnostic & Troubleshooting 6 - 7
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 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 C-2 and C-3. 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 is not oper-
ating properly.
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
UV1
DC Bus Undervolt
DC Bus Undervoltage
The DC bus voltage is
≤ L2-05
208-240Vac: Trip point is ≤ 190Vdc
480Vac: Trip point is ≤ 380Vdc
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
Voltage fluctuation of the input
power is too large
Check the input voltage
Table 6.1 Fault Displays and Processing
Digital
Operator Display
Description Cause Corrective Action
TM_E7_01_07182008.book Page 7 Wednesday, July 23, 2008 2:35 PM