Omron SYSDRIVE 3G3MV User Manual page 262

Maintenance Operations
FbL Feedback loss fault (FbL)
A feedback input was
interrupted during PID control
execution. (This fault is
detected when an input level
below the feedback loss
detection level set in n137
persists for longer than the
feedback loss detection time
set in n138.)
PF (See Main circuit voltage fault
note.) (PF)
The main circuit DC voltage
has oscillated erroneously
when regeneration was not
being performed.
This fault is detected when a
voltage fluctuation greater
than the input open-phase
detection level set in n166
persists for longer than the
input open-phase detection
time set in n167.
LF (See Output open-phase fault
note.) (LF)
An open phase has occurred
at the Inverter's output.
This fault is detected when a
current in any of the Inverter
output phases less than the
output open-phase detection
level set in n168 persists for
longer than the output
open-phase detection time set
in n169.
· Feedback wiring error.
® Check for and correct any cable disconnection or faulty
wiring.
· Feedback sensor error
® Check sensor status and replace any defective sensors.
· PID target value input error or feedback loss detection set-
ting error
® Correct the target value input so that it is outside of the
feedback loss detection range. Correct the feedback loss
detection parameter settings (n137, n138).
· Feedback input circuit error
® Replace the Inverter.
· Momentary power failure.
® Either apply countermeasures against momentary power
failures or disable the input open-phase detection.
· Input power supply open phase.
® Check for and correct any main circuit power supply
disconnections or faulty wiring.
· Excessive input power supply voltage fluctuation or bad line
voltage balance.
® Check the power supply voltage. Apply measures to
stabilize the power supply, or disable the input
open-phase detection.
· Main circuit capacitor failure.
® If this fault is occurring frequently and there is no error at
the power supply, replace the Inverter or disable the input
open-phase detection. (Also check the usage time with
the accumulated operating time function.)
· Output cable is disconnected.
® Check for and correct any output cable disconnections or
faulty wiring.
· Motor winding disconnected.
® Check the motor's line resistance. If winding is broken,
replace the motor.
· Output terminal screws are loose.
® Check and tighten the output terminal screws.
· Inverter output transistor open breakdown.
® Replace the Inverter.
Chapter 8
8-9