
8. Fault Diagnosis
169
Flashing
Detected as
an alarm
only. Fault
contact out-
put is not ac-
tivated.
CE (MEMOBUS) com-
munications fault
Check the following:
• Communicaiton
devices
or communication sig-
nals.
• PLC is not faulty.
• Transmission cable is
connected properly.
• Any loose terminal
screws do not result in
improper contact.
• Wiring is made properly.
Flashing
FBL (PID feedback loss
detection)
PID feedback value dropped
below the detection level
(n137). When PID feedback
loss is detected, the Inverter
operates according to the
n136 setting.
Check the mechanical sys-
tem and correct the cause, or
increase the value of n137.
Flashing
Option card communica-
tions fault.
• Communication
fault
has
occurred the mode where
the communications
option card was used and
a run command or fre-
quency reference was
input from the PLC.
• Communication
fault
has
occured in a mode that
RUN command and fre-
quency reference are set
from the communication
option card.
Check the following:
• Communications
devices
or communications sig-
nals.
• PLC is not faulty.
• Transmission cable is
connected properly.
• Any loose terminal
screws do not result in
improper contact.
• Wiring is made properly.
• Communication
option
card is inserted correctly.
Flashing
OH3 (Inverter overheat
alarm)
The Inverter overheat alarm
(OH3) was input from a multi-
function input terminal (S1
and S7).
• Clear the multi-function
input terminal’s Inverter
overheat alert input.
• Check that the wiring is
made properly.
• Check that a signal is not
input from the PLC.
Alarm Display
Inverter
Status
Description
Causes and
Corrective Actions
Digital
Operator
RUN (Green)
ALARM (Red)
or