Omron SYSDRIVE 3G3MV User Manual page 270

Maintenance Operations
Fault Fault name and Meaning
display
FbL (flashing) 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.)
oH3 Inverter overheating warning (oH3)
An Inverter overheating warning signal
was input from an external control
terminal set to multi-function input.
CE Communications time over (CE)
RS-422 or RS-485 communications
were not properly carried out within 2
s. (Detected when n151 is set to "3.")
Probable cause and remedy
· 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 setting 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.
· Clear the Inverter overheating warning signal.
· Eliminate the cause of the warning signal input.
· A short-circuit, ground fault, or disconnection has
occurred on the communications line.
® Check and correct the line.
· The termination resistance setting is incorrect.
® In the case of RS-422 communications, set
pin 1 of SW2 of all Inverters to ON. In the
case of RS-485 communications, set pin 1 of
SW2 of only the Inverter located at each end
of the network to ON.
· Noise influence.
® Do not wire the communications line along
with power lines in the same conduit.
® Use the twisted-pair shielded wire for the
communications line, and ground it at the
Master.
· Master's program error.
® Check and correct the program so that
communications will be performed more than
once every 2-s period.
· Communications circuit damage.
® If the same error is detected as a result of a
self-diagnostic test, change the Inverter.
Chapter 8
8-17