76
Technical Information
Service Manual
●
Outdoor Unit(07/09/12K)
1. Cooling mode:
Working condition and process of cooling mode:
①
 When Tindoor  ambient  temperature≥Tpreset, unit enters into 
cooling mode. Indoor fan, outdoor fan and compressor start 
operation. Indoor fan operates according to set fan speed.
②
 When Tindoor ambient temperature≤Tpreset-2
℃
, compressor 
stops operation and outdoor fan will stop 30s later. Indoor fan 
operates according to set fan speed.
③
 When Tpreset-2
℃<
Tindoor ambient temperature
<
Tpreset, 
unit operates according to the previous status.
Under cooling mode, 4-way valve is not energized. Temperature 
setting range is 16~30
℃
. If compressor stops because of 
malfunction in cooling mode, indoor fan and swing motor will work 
according to the original status.
2. Drying mode
(1) Working condition and process of drying mode
①
 When Tindoor ambient temperature
>
Tpreset, unit will be in 
drying mode. Outdoor fan and compressor start operation while 
indoor fan will operate at low fan speed.
②
 When Tpreset-2
℃
≤Tindoor ambient temperature≤Tpreset, unit 
operates according to the previous status.
③
 When Tindoor ambient temperature
<
Tpreset-2
℃
, 
compressor stops operation and outdoor fan will stop 30s later.
(2) Under drying mode, 4-way valve is not energized. Temperature 
setting range is 16~30
℃
.
(3) Protection function: same as in cooling mode.
3. Fan mode
(1) Under this mode, indoor fan can select different fan speed 
(except Turbo) or auto fan speed. Compressor, outdoor fan and 
4-way valve all stop operation.
(2) In fan mode, temperature setting range is 16~30
℃
.
4. Heating mode
Working condition and process of heating mode:
①
 When Tpreset-(Tindoor ambient temperature-
Tcompensation)≥1
℃
, unit enters into heating mode. Compressor, 
outdoor fan and 4-way valve start operation.
②
 When -2
℃<
Tpreset-(Tindoor ambient temperature-
Tcompensation)
<
1
℃
, unit operates according to the previous
status.
③
 When Tpreset-(Tindoor ambient temperature-
Tcompensation)≤-2
℃
, compressor stops operation and outdoor 
fan will stop 30s later. Indoor fan will be in residual-heat blowing 
status.
④
 When unit is turned off under heating mode or changed to other 
modes from heating mode, 4-way valve will be power-off 2min 
after compressor stops working (compressor is in operation status 
under heating mode).
⑤
 When Toutdoor ambient temperature
>
30
℃
, compressor 
stops operation immediately. Outdoor fan will stop 30s later.
⑥
 Under the condition that compressor is turned on, when unit 
is changed to heating mode from cooling or drying mode, 4-way 
valve will be energized in 2~3mins delay.
Note: Tcompensation is determined by IDU and ODU. If IDU 
controls the compensation temperature, then Tcompensation is
determined according to the value sent by IDU to ODU; If 
IDU does not control the compensation temperature, then 
Tcompensation will default to 3
℃
 by the ODU.
5. Freon recovery mode
After the Freon recovery signal from IDU is received, cooling at 
rated frequency will be forcibly turned on to recover Freon.
Indoor unit will display Fo. If any signal from remote controller is 
received, unit will exit from Freon recovery mode and indoor unit 
stops displaying Fo.
6. Compulsory defrosting
If unit is turned on under heating mode and set temperature is 
16
℃
 (by remote controller), press “+, -, +, -, +, -” within 5s, unit 
will enter into compulsory defrosting mode and send the signal 
to ODU. When the compulsory defrosting signal from ODU is 
received, IDU will exit from the compulsory defrosting mode and 
stop sending the signal to ODU.
After ODU receives the compulsory defrosting code, it will start 
compulsory defrosting. Defrosting frequency and opening
angle will be the same as in normal defrosting mode. When 
compulsory defrosting is nished, the complete unit resumes
original status.
7. Auto mode
Auto mode is determined by controller of IDU. See IDU logic for 
details.
8. 8
O
C heating
Set temperature is 8
O
C. Display board of IDU displays 8
O
C. Under 
this mode, “Cold air prevention” function is shielded.
If compressor is operating under this mode, fan speed will adjust 
according to auto fan speed; if compressor stops operation
under this mode, indoor fan will be in residual-heat blowing status.
When power  on,  communication light  will be  blinking  in a 
normal way (after receiving a group of correct signals,
blinking stops  for  0.2s~0.3s). If  theres no  communication, 
communication light will be always on. If other ODU has
malfunction, communication light will be on for 1s and off for 
1s in a circular way.