Yaskawa F7 Drive User Manual - Manual (Page 133)

Diagnostics & Troubleshooting 6 - 8
Table 6.1 Fault Displays and Processing (continued)
Digital
Operator Display
Description Cause Corrective Action
PF
Input Pha Loss
Input Phase Loss
Drive input power supply has an open phase
or has a large imbalance of voltage.
Detected when L8-05 = 1 (enabled).
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.
PGO
PG Open
PG Disconnection (Detection with
Software)
Detected when F1-02 = 0 to 2 and
A1-02 = 1 or 3.
Detected when no PG (encoder) pulses are
received for a time longer than the setting in
F1-14.
There was a break in the PG
wiring. Fix the broken / disconnected
wiring.
The PG was wired incorrectly. Fix the wiring.
Power wasn’t being supplied
to the PG.
Supply power to the PG properly.
Braking mechanism is
possibly engaged. Check for open circuit when using
brake (motor).
PGOH
PG Open
HARDWARE
<3021>
PG Disconnection (Detection with
Hardware)
Detected when F1-02 - 0 to 2 and F1-25 = 1
(PG-T2 or PG-Z2) and / or F1-26 = 1 (PG-
Z2) and A1-02 = 1 or 3.
Detected when no PG (encoder) pulses are
received.
There is a break in the PG
wiring. Fix the broken / disconnected
wiring.
The PG was wired incorrectly. Fix the wiring.
Power is not being supplied to
the PG. Supply the proper power required
by the PG encoder.
—
Check for an open circuit when
using the brake (motor).
PUF
DC Bus Fuse Open
DC Bus Fuse
Detects if the DC bus fuse has opened.
Warning:
Never run the Drive after replacing the
DC bus fuse without checking for shorted
components.
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 heatsink mount
resistor is activated when L8-01 = 1.
This fault is only applicable when using the
3% duty cycle resistor, which is mounted on
the Drive’s heatsink. For all other resistors,
set L8-01 = 0.
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 built-in dynamic braking transistor is
not operating properly.
Started dynamic braking tran-
sistor high DC bus voltage,
defective dynamic braking
resistor.
Cycle power to the Drive.
Replace defective dynamic
braking transistor or resistor
.
Monitor DC bus voltage.