17
Technical Information
Service Manual
ķ
Operation condition and process for fan mode
In fan mode, the IDU fan motor operates at set speed, while the compressor and the ODU fan motor stop. 4-way valve is de-energized
(4-way valve is not available for cooling only unit). Temperature setting range is 16~30
ć
.
ĸ
Display: Operation icon, set temperature.
Ĺ
Protection function
In fan mode, there are overcurrent protection and blocked protection of IDU fan motor. Please refer to corresponding protection function
under cooling mode for details.
(5) Heating mode(no heating mode is not available for cooling only unit)
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Operation conditioner and process for heating mode
In heating mode, 4-way valve is energized. Temperature setting range is 16~30
ć
ĸ
Display: Operation icon, heating icon, set temperature.
Ĺ
Defrosting condition and process
For ensusing heating effect, air conditioner will defrost automatically according to defrosting status on outdoor unit. During defrosting,
heating icon is bright for a while and then off for a while.
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Protection function
ƹ
Overheating prevention protection
ƹ
Noise silencing protection
When turning off the unit or during mode switchover, the 4-way valve is closed. In order to decrease noise, the 4-way valve will delay
2mins to be closed.
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Overcurrent protection ( this protection function is not available for those models whose cooling capacity ≤12000Btu/h)
During operation process, if controller detected that system current exceeds the limit value for 3s consecutively(overcurrent), the
system stops operation. About 3mins later, if overcurrent is released, the system will resume original operation. If overcurrent protection
occurs for 6 times consecutively, and resume operation time won’t exceed 6min every time, overcurrent protection information will be
displayed. After turning off the unit, display won’t be displayed.
If turn on the unit again, the system will be restated up again. Overcurrent protection information will be eliminated.
Please refer to maintenance part for display information and disposal method for details.
ƹ
Locked protection to IDU fan motor
During operation of IDU fan motor, if controller detected that the rotation speed of IDU fan motor less than 300/min or stop rotation, the
motor operates abnormally. In order to prevent damage to motor, controller will protect automatically, the system stops operation and
blocked information of IDU fan motor will be displayed. After turning off the unit, display won’t be displayed.
If turn on the unit again, the system will be restated up again. Blocked information of IDU fan motor will be eliminated. (For some mod-
els, they can only be restated up after re-energized)
Please refer to maintenance part for display information and disposal method for details.
T
preset
+4
T
preset
+2
Stop heating
Original operating status
Start heating
valve
Outdoor unit
Intdoor unit
Compressor
min.
min.
T
amb
.
Set fan speed
Set fan speed
Reversing
ƹ
When Tamb.-Tsupplementary≤Tset-1 ,
ć
the unit starts heating operation. In this case, the 4-way valve is energized; the compressor
and ODU fan motor run simultaneously; the IDU fan motor runs after a while to prevent blowing out cold air.
ƹ
When Tamb.-Tsupplementary≥Tset+1
ć
, the compressor and ODU fan motor stop; the 4-way valve remains energized; the IDU fan
motor blows residual heat for a while at set speed to prevent high temperature inside the unit.
ƹ
When Tset-1
ć˘
Tamb.-Tsupplementary
˘
Tset+1
ć
, the unit will maintain its previous running status.
During operation, if Ttube≥55
ć
is detected by the controller, the ODU fan motor stops operation; When Ttube returns to normal, the
ODU fan motor resumes operation.
(4) Fan mode
◆
Other protection is same as that under cooling mode.
6 min.
6 min.
3 min.
60S
60S
