Gree GWH07AAAXA-K3NNA5A Service Manual page 38

Service Manual
◆ When Tamb. >Tset+2℃ , the system starts drying and cooling.
In this case, the compressor and the ODU fan motor operate, and
the IDU fan motor operates at low speed.
◆ When Tset-2℃ ≤Tamb. ≤Tset+2℃ , the system will start drying.
In this case, the IDU fan motor operates at low speed; the com-
pressor and the ODU fan motor operate for 6 minutes and stop for
4 minutes in cycle.
◆ When Tamb.<Tset-2℃ , the compressor and the ODU fan mo-
tor stop, while the IDU fan motor runs at low speed.
In drying mode, the 4-way valve is de-energized (4-way valve is
not available for cooling only unit); Temperature setting range is
16~30℃ . Fan speed Can't be adjusted.
② Protection function
◆ Freeze protection
During dying and cooling operation, when the controller detected
that Ttube≤0℃ for a period of time consecutively, the system will
enter into freeze protection. In that case, the compressor and the
ODU fan motor stops operation, while the IDU fan motor operates
at low speed. When freeze protection is release and the compres-
sor has stopped for 3min, the system will resume original opera-
tion.
During drying operation, when the controller detected that
Ttube≤0 ℃ for a period of time consecutively, the system enters
into freeze protection. In that case, the compressor, the ODU fan
motor stops operation, while the IDU fan motor operates at low
speed. When freeze protection is release and the compressor has
stopped for 4min, the system will resume original operation.
◆ Other protection is same as that under cooling mode.
(4) Fan mode
① 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℃ .
② 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)
Technical Information
① Operation conditioner and process for heating mode
◆ When Tamb-Tcompensation≤Tpreset-1 ℃ , unit will operate in
heating mode. 4-way valve will be energized while compressor
and outdoor fan starts operation at the same time. Indoor fan will
start some time later so that air condition wont blow out cold air.
◆ When Tamb-Tcompensation≥Tpreset+1 ℃ , compressor and
outdoor fan will stop operation while 4-way valve is still power
on. Indoor fan will continue operation for a while at set fan speed
to blow out the residual heat so that temperature within the air
conditioner wont be too high.
◆ When Tpreset-1 ℃ ＜ Tamb-Tcompensation ＜ Tpreset+1 ℃ ,
system will maintain its previous working status.
In heating mode, 4-way valve is energized. Temperature setting
range is 16~30℃ .
② Defrosting condition and process
For ensusing heating effect, air conditioner will defrost
automatically according to defrosting status on outdoor unit.
During defrosting, heating icon will be on and off.
④ Protection function
◆ Overheating prevention protection
During operation, when controller detects that Ttube≥55 ℃ ,the
ODU fan motor stops operation; When Ttube is resumed normally,
the ODU fan motor resumes operation.
◆ 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.
◆ 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 wont exceed 6min every time, overcurrent protection
information will be displayed. After turning off the unit, display
wont 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.
◆ Locked protection to IDU fan motor
35