UNIT MAINTENANCE &
SER
VICE GUIDE
UNIT MAINTENANCE &
SER
VICE GUIDE
TROUBLE SHOOTING
P35 OF 44
TROUBLE SHOOTING
P36 OF 44
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
The circuit on API has malfunction,
replace the outdoor unit API.
Whole unit's
current testing
malfunction
Off 3s
blink 13
times
U5
■
□
☆ ■
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Please refer to troubleshooting (IPM
protection, compressor lose steps,
compressor current overcorrect
protection).
P5
Off 3s
blink 15
times
Compressor
current
overcorrect
protection
□ ☆ □ □
Under the heating mode,
compressor running, indoor/outdoor
fan motor stop working
It is normal function
H1
H2
Off 3s
blink
once
Off 3s
blink
twice
Defrosting
Electrostatic
dedust
protection
Cooling, dehumidifying; compressor
stops running, indoor fan motor
works. Heating: all will stop running
1) Wire terminal OVC-COMP loosen
or circuit, has problem, the
resistance of SAT should be lower
than l ohm.
2) Please refer to troubleshooting
(exhaust/overload protection)
H3
Off 3s
blink 3
times
Compressor
overload
protection
18
19
20
21
22
□ ☆
□
☆
Pls refer to troubleshooting
H4
H5
Off 3s
blink 4
times
Off 3s
blink 5
times
System
abnormal
IPM protection
Cooling, dehumidifying; compressor
stops running, indoor fan motor
works. Heating: all will stop running
Pls refer to troubleshooting
Cooling, dehumidifying; compressor
stops running, indoor fan motor
works. Heating: all will stop running
23
24
■
■ □ ■
Overload normal works, compressor
running, frequency declines.
Pls refer to troubleshooting.
Pls refer to troubleshooting.
Replace the outdoor control board
API.
Replace the outdoor control board
API.
Replace the outdoor control board
API.
Pls refer to Part 3 capacitor charging
fault of troubleshooting.
To check whether the ambient
Temp. of IPM is too high or the heat-
sinhing of IPM is dirty else replace
the outdoor baord API.
HC
H7
H0
Lc
U1
EE
PU
P7
P8
Off 3s
blink 6
times
Off 3s
blink 7
times
Off 3s
blink 10
times
Off 3s
blink 11
times
Off 3s
blink 13
times
Off 3s
blink 15
times
Off 3s
blink 17
times
Off 3s
blink 18
times
Off 3s
blink 19
times
PFC prtection
Compressor
lose steps
Heating, anti-
high temp.
declines
Starts up fail
Compressor
current testing
circuit
malfunction
EEPROM
malfunction
Capacitor
charge
malfunction
Module sensor
circuit diagram
Module
temp.
over high
protection
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Pls refer to troubleshooting.
Pls refer to troubleshooting.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
Cooling, dehumidifying: compressor
stops running, indoor fan motor
works. Heating: all will stop running.
25
26
27
28
29
30
31
32
33
34
35
DC Bus
voltage dips
U3
off 3s
blink 20
times
cooling, dehumidifying: compressor
will stop, indoor fan motor works,
Heating: all will stop.
Power voltage is not staable.
cooling, dehumidifying: compressor
will stop, indoor fan motor works,
Heating: all will stop.
1) Check the Input voltage if the
Voltage is lower than 150VAC,
restart the machine when the
power supply is normal.
2) Checking the reactor L
connection.
off 3s
blink 21
times
PL
Low DC Bus
voltage
protection
□ ■
☆
☆
□ ☆ ■ ☆
☆
☆
□
■
☆
☆ □
□
☆
□
■ □
□ □ □ ■
■
□
□ ■
□ □ ■ ☆
■
☆
□
■
■
■
■
□
■
■
□
□
■
■
Outdoor temp. sensor hasn' t
connected well, or damaged,
please refer to the sensor resistance
value for checking.
Cooling, dehumidifying: compressor
will stop, indoor fan motor will work.
Heating: all will stop.
Off 3s
blink
18
times
Outdoor
condensor
sensor open
circuit, short
circuit
12
13
14
15
16
□
□
☆ □
F4
Cooling, dehumidifying: after running
for 3mins later, the compressor will
stop to run, indoor fan motor will
start to run. Heating: after run 3mins
later, all will stop to run.
1) Exhaust temp sensor hasn' t
connected well, or damaged,
please refer to the sensor ;
resistance value for checking.
2) Sensor head hasn' t insert into
the copper tube.
Off 3s
blink
5
times
F5
Outdoor air
exhaust
sensor
open circuit,
short circuit
Please refer to troubleshooting
1) Input power supply is too low;
2) System voltage is too high,
overload is too much.
Overload normal operation,
compressor is running, frequency
descending.
Overload normal operation,
compressor is running, frequency
descending.
Off 3s
blink
6 times
Off 3s
blink
8 times
F8
F6
Overload limit/
descending
frequency
Over current
need
frequency
descending
□
□
□
☆
☆
☆
☆
1) Overload is too much, ambient
temp. is too high;
2) Refrigerant is short;
3) Electric expansion malfunction.
Overload normal operation,
compressor is running, frequency
descending.
Off 3s
blink
9 times
F9
Air exhaust
over high
need frequency
descending
■ □ ■
■ ■
■
□
□
□
□
17
1) Testing wire terminal L and N
position If higher than 265VAC,
please cut off the power supply
and restart until back to normal;
2) If input voltage is normal, testing
the voltage of electrolytic
capacitor on API after turn on the
unit. There may be some problem
and replace the API if the
electrolytic capacitor voltage
range at 200-280V.
Cooling, dehumidifying, compressor
stop running fan motor works.
Heating: all will stop.
Off 3s
Blink
11
times
PH
DC generatrix
voltage
is too high
☆
Outdoor room temp. sensor hasn' t
connected well, or damaged, please
refer to the sensor resistance value
for checking.
Cooling, dehumidifying: compressor
will stop, indoor fan motor will work.
Heating: all will stop.
Off 3s
blink
three
times
F3
Outdoor
ambient
sensor circuit
open, circuit
short
□
□
☆ ■
11
36
Overload normal works, compressor
running frequency declines.
Whole unit break for 30mins and
discharge, to check the outdoor
control board API's IPM module
coolant whether is short, the radiator
is tightened. If above phenomenon
is not ok, please improve or replace
the control board API.
EU
IPM temp. is
too high limit/
decrease
frequency
■
■
■
☆
37
Four-way
valve
abnormal
U7
■
☆
□
□
This malfunction happened, only in
heating mode, all will stop to run.
1) Power supply voltage is lower
than AC175V.
2) Wire terminal 4V loosen or wire
break.
3) 4V damaged, replace 4V.
38
39
■
☆ □
■
U9
Outdoor unit
zero-cross
detecting error
Cooling: compressor will stop,
indoor fan motor works.
Heating: all will stop.
Replace the outdoor control board
APl.
Anti-freezing
limit/decrease
frequency
All loads work normally but the
running frequency limited or
decrease.
FH
■
□
■ ■
Indoor unit air return is poor or fan
speed is too low.
Notes:
Subject to continuous engineering change and product improvement without notice.
YMGI, Engineered Comfort Products for A Sustainable and Efficient Green World !
YMGI, Engineered Comfort Products for A Sustainable and Efficient Green World !
