Omron SYSDRIVE 3G3MV Setup Manual page 106

Maintenance Operations
Fault display Warning name and meaning
%h3
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
• 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 4
4-13