Service manual
24
10.3
Problem Solution
Problem
Cause
Remedy
Power failure
Check the power cord.
Transformer failure
Check the input and output on transformer.
Replace it if failure.
Not operating
Indoor main control board failure Replace it after checked failure.
Check wiring. Correct if there is any wrong
connection.
Check the sequence of compressor wiring.
Correct if in wrong sequence.
Check the resistance between P-N
、
P-U
、
P-V
、
P-W
、
N-U
、
N-V
、
N-W on inverter control board.
Replace if any one of this group is fault.
Module protection
The frequency converter module
protect against current
、
voltage
and temperature for 4 times
within 1 hour.
Replace the compressor after checked failure.
Lack of refrigerant.
Check leakage. Recycle the refrigerant.
Correct and recharge if there is any leakage in
the refrigerant system.
Over-current protector failure.
Check
the
resistance
of
compressor
over-current protector. Replace if failure.
Compressor
top
protection
against
temperature
Outdoor main control board
failure.
Replace it after checked failure.
Temperature sensor failure.
Replace after checked failure.
Open or short circuit
of
outdoor
temperature sensor.
Outdoor main control board
failure.
Replace after checked failure.
Temperature sensor failure.
Replace after checked failure.
Open or short circuit
of indoor temperature
sensor.
Indoor
main
control
board
failure.
Replace after checked failure.
Power failure.
Wait if checked the power failure is really too
low.
Over load or too low
voltage protection.
Power control board failure.
Replace after checked failure.
Wiring failure.
Correct if the wiring of indoor fan motor is
loosen.
Indoor fan motor failure.
Check the input of indoor fan motor. Replace if
failure.
Fan speed out of
control.
Indoor
main
control
board
failure.
Replace after checked failure.
Zero-crossing
examination error
Indoor
main
control
board
failure.
Replace after checked failure.
EEPROM data error
Indoor
main
control
board
failure.
Replace after checked failure.
Wiring failure.
Check wiring. Correct if there is any wrong
wiring or the wiring is loosen.
Inverter control board failure.
Replace after checked failure, no +5V power.
Outdoor main control board
failure.
Replace if the LED is not on.
Indoor
main
control
board
failure.
Replace if the photo coupler on indoor main
control board is failure.
Indoor/outdoor units’
communication
protection.
Outdoor power control board
failure.
Replace if the photo coupler on outdoor main
control board is failure.
