Description Of Each Control Operation; Basic Functions; Protection Function; Defrosting - Gree GVH48AH-M3DNA5A Service Manual

1.Basic Functions

1.1 Cooling Mode
When Tamb.≥Tpreset+1 , the unit will run in cooling mode. Meanwhile, compressor and outdoor fan will run. Indoor fan will
run at setting fan speed;
When Tamb.≤Tpreset-1 , the unit will stop running in cooling mode. Compressor and outdoor fan will stop running, while
indoor fan is still running at setting fan speed;
When Tpreset-1 <Tam .<Tpreset+1 , the unit will keep previous running status;
1.2 Dry Mode
When Tamb>Tpreset+2
run at low fan speed.
When Tpreset-2 ≤Tamb. ≤Tpreset+2 , compressor and outdoor fan will run for 6mins and then stop running for 4mins and
they will run like that circularly. Indoor fan will run at low fan speed;
When Tamb.<Tpreset-2 , compressor and outdoor fan will stop running. Indoor fan will run at low fan speed.
1.3 Heating Mode
When Tamb≤Tpreset-1 , the unit will run in heating mode and the corresponding load will start running. Indoor fan will run at
the condition of anti cold wind.
When Tamb.≥Tpreset+1 , the corresponding load will be stopped. Indoor fan will run at setting fan speed and the condition of
blowing residual heat.
When Tpreset<Tamb<Tpreset+1 , the unit will keep previous running status.
1.4 Fan Mode
Indoor fan will run at setting fan speed. Compressor, outdoor fan and reversing valve will stop running.
1.5 Auto Mode
In this mode, the unit will decide its running mode according to the ambient temperature.
When Tamb>26 , the unit will run in cooling mode. Internal setting temperature is 26 ;
When 20 ≤Tamb. ≤26 , the unit will run in dry mode. Internal setting temperature is 24 ;
When Tamb.<20 , the unit will run in heating mode. Internal setting temperature is 20 . When Tamb.≥24 , the unit will quit
from the heating mode. As for the cooling only unit, when Tamb.<20 , the unit will run at fan mode and the internal setting
temperature is 20 . When Tamb≥24 , the unit will quit from the fan mode.

2. Protection Function

2.1 Indoor Antifreezing Protection
When antifreezing protection is detected, the corresponding load will be stopped. After the antifreezing protection is released,
controller will run at setting mode. Buttons won't be shielded during the antifreezing protection.
2.2 High Pressure Protection of System
When high pressure protection is detected, the corresponding load will be stopped. All button and remote control signal will be
shielded and E1 will be displayed; after high pressure protection of compressor is released, all buttons and remote control
signal will become normal.
2.3 Low Pressure Protection of System
When low pressure protection is detected for the first time, the corresponding load will be stopped and the indicator will blink. If
the low pressure protection is detected for twice successively, the corresponding load will be stopped and E3 will be displayed.
They can't resume automatically.
2.4 High Temperature Protectionfor Discharge Pipe
When high temperature protection for discharge pipe is detected, the corresponding load will be stopped. E4 will be displayed.
2.5 Indoor High Temperature Resistant Protection
When high temperature resistant protection is detected, the corresponding load will be stopped.
2.6 Overcurrent Protection
When overcurrent protection is detected, the corresponding load will be stopped and E5 will be displayed.
3. Other Function

3.1 Defrosting

The unit will judge according to the tube temperature and ambient temperature, when it's detected that the outdoor condenser
is frosting, the unit will start defrosting. Indoor fan and four-way valve will stop running. After defrosting is finished, the unit will
start heating normally. During the time of defrosting, dual 8 will display H1.
3.2 Swing Function
Users can start up or stop the function of up&down swing, right&left swing.
the unit will run at cooling mode. Meanwhile, compressor and outdoor fan will run. Indoor fan will