Service manual

17
3 Troubleshooting
Problem Check point Corrective measure
Remove the connector from the controller board and connect diagnostic
LEDs.
Pulses will be issued for 10 seconds when the power is turned on.
It indicates that there is an abnormality in the operating circuit if
any LEDs don't turn on or off.
If the linear expansion valve becomes locked and the motor is still operating,
the motor will emit a clicking noise and will not function. This clicking noise
indicates an abnormality.
Use an all-purpose electrical meter to measure the resistance between the
different coils (red-white, red-orange, brown-yellow, brown-blue). Normal
resistance is within a range of 150'±10%.
In order to check the linear expansion valve, operate one indoor unit in the
fan mode and another in the cooling mode. Then, use the outdoor multi
controller board to operate the monitor and check the pipe temperature of the
indoor unit (RT12). The linear expansion valve should be fully closed when
the fan is operating. The temperature measured by the temperature sensor
will drop if there is any leakage.
If the measured temperature is significantly lower than that on the remote
controller, this indicates that the valve is not closed. It is not necessary to
replace the linear expansion valve if the leak of refrigerant is small and does
not cause a malfunction.
1 Check improperly connected connector terminals and the wire colors.
2 Remove the connector on the controller board side and check electrical
conductance
Malfunction in
microprocessor
operating circuit
Locked expansion
valve
Short circuit or broken
circuit in expansion
valve motor coil
Valve does no close
completely
Incorrect connection
or connection failure
Replace the R-Converter
controller board
Replace the linear
expansion valve
Replace the linear
expansion valve
Replace the linear
expansion valve if there
is a major leak of
refrigerant.
Continuity check of
wrong part.
6
5
4
3
2
1
1k" LED
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