Troubleshooting Guide
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Only training and service purposes.
1. Auto addressing is not done
2. Communication cable is not connected
3. Short circuit of communication cable
4. Indoor unit communication circuit fault
05 5. Compressor Module communication circuit fault
6. Not enough distance between power and
communication cable?
7. T phase line disconnection or N phase connected.
Error
No.
Error Type
Error Point
Main Reasons
No signal communication
between indoor &
Compressor Module.
Indoor & Compressor
Module communication
error
Does all the IDUs show
same error code CH05?
Is outdoor PCB LED
blinking?
Yes
Yes
No
Is main circuit breaker off?
No
Check the main power
supply at the ODU
terminal block?
Improper connection of power supply cable
Main power supply problem
Yes
No
Yes
No
Outdoor PCB fault
Replace after checking
Re connect communication cable
No
Yes
Indoor PCB fault
Replace after checking
* (Note1) communication from IDU is normal if voltage
fluctuation(-9V ~ +9V) exists when checking DC voltage
of communication terminal between IDU and ODU
Is total number of indoor
units connected displayed
after auto addressing?
No
END
* If the DC voltage between communication terminal A, B
of indoor unit is fluctuate within (-9V~+9V) then
communication from outdoor unit is normal
Check the insulation of compressor
compressor and replace if required
Check the capacity of main circuit
breaker and replace if required
Check T phase line connetion
If all ok,
Turn on main circuit breaker
Replace outdoor PCB after
checking
Replace TRANS after checking
Replace the PCB of indoor unit
displayed error
Re-connect after check the
communication cable of indoor
unit displayed error**
Check if the
communication cable is
properly connected
to indoor / outdoor
terminal block?*
n
Error diagnosis and countermeasure flow chart
