Trouble 9: AC current over current protection or current transducer damaged, or compressor blocked rotor,
compressor great vibration, compressor abnormal startup, state detecting curcuit abnormal or compressor damaged.
yes
PCB is faulty
and repalce it,
check again
replace sensor
and check
again
replace sensor
and check
again
check if the
sensor resistor
value is correct
check if the sensor
is in open circuit or
the connection port
to PCB is in good
condition
re-fix the
sensor and
check again
as per the wiring
diagram, check if
connection port
between sensor and
PCB is correct
yes
no
no
yes
no
Trouble 8: Outdoor unit alarms sensor failure
Check the failure code on outdoor indicator board (5-lamp)
Trouble 7: Outdoor unit failure
start
The former twice failure can be resumed automatically, if outdoor board occurs this failure always, and can not be
resumed for a long time, that shows:
1. Power module (SPDU) damaged, please replace the power module, then re-wiring as per the wiring diagram (70%
possibility)
2. Short circuit in power board results in the power module damaged (15
％
possibility)
3. Damaged compressor results in this failure (10
％
possibility)
4. Main control board is faulty, replace it (5
％
possibility)
replace outdoor
motor and check
again
check if the
outdoor motor
has power input
replace pressure
switch connector, shut
off and be electrified
again, re-check
replace pressure switch
connector, shut off and
be electrified again,
re-check
replace main
control board
and check again
if outdoor fan
motor cannot
startup normally
in cooling mode
check if the 2 straight
lugs on the pressure
switch are in good
condition
yes
yes
yes
no
no
no
check if the connector
between pressure
switch and PCB is
fixed badly or damaged
Trouble 10: High pressure failure
Reasons:
1. Over high system pressure results that the unit stop, and the compressor protection will work. The failure can be
resumed.
2. Pressure switch wire is not fixed well or in open circuit.
no
start
-63-
Commercial Air Conditioner
Model: AU18
/22
2XFERA
AS072/092/122XVERA
