Gree GWH09RB-K3DNA2C Service Manual page 30

Function and Control
(3) HEAT mode
The condition and process of heating
If T ≤T +2˚C , HEAT mode will act, the compressor, outdoor fan and reversal valve will run, the indoor fan will delay
amb preset
3min to stop at the latest
If T +2˚C < T
preset amb
If T ≥T +5˚C , the compressor will stop, the outdoor fan will delay 30sec to stop and indoor fan will blow 60S at low
amb preset
speed, the fan speed cannot be shifted within blow residual heat.
In this mode, the temperature setting range is 16
The air conditioner will adjust the running frequency of the compressor automatically according to the change of ambient
temperature.
When the unit is turned off in HEAT mode, or switched to other mode from HEAT mode, the four-way valve will be powered
of f after the compressor stops.
When compressor is running (not including each malfunction and protection):
a.When outdoor ambient temperature≥20
fan speed is high or super high, it will keep the same.
b.When outdoor ambient temperature≤18 , the fan speed will resume set fan speed.
c. When 18 outdoor ambient temperature 20 , it will run at present fan speed (set fan speed or high fan speed); but
when first exiting cold air prevention after entering heating mode, it will run in set fan speed.
The condition and process of defrosting
When frost is detected in the condenser, the system will enter into defrosting state. When defrosting starts, the compressor and
indoor fan will stop, and the outdoor fan and four-way valve will delay 30 seconds to stop. The compressor will start after 15 seconds
and then defrosting will be started. When the compressor has run for 7 minutes or defrosting is finished, the compressor will stop.
After 30 seconds the four-way valve opens and after another 60 seconds, the compressor and outdoor fan resume running. The
indoor fan will delay 3 minutes to run at the latest and temperature on the display panel shows H1.
Protection function
Anti-cold-wind protection
In HEAT mode, in order to prevent the indoor unit from blowing out cold wind, each time the compressor starts, the indoor fan
will delay 3 minutes after the compressor to run at the latest and it can adjust fan speed automatically when temperature is low.
Overcurrent protection
Overcurrent protection is the same with that in COOL mode.
3.Protection
Cold air prevention
The unit is started under heating mode (the compressor is ON):
In the case of T
speed with a time lag of 2 minutes. Within 2 minutes, if T
1-minute operation at low speed, the indoor fan will be converted to operation at preset speed. Within 1-minute low speed
operation or 2-minute non-operation, if T
In the case of T
will be converted to preset speed. Within one-minute low speed operation, if T
to preset speed.
< T +5˚C ,the unit will keep running in the original mode.
preset
and indoor fan speed is low or medium, the fan speed will turn to high; if indoor
T preset +5
T +2
preset
T .
amb
m
Compressor
Outdoor fan
Indoor fan min.
Reversing
valve
Run
The period of defrosting
30s
Four-way valve
Compressor
30s
Outdoor Unit
Indoor Unit
Run
<24 : if T 40
indoor amb. tube
tube
24 : if T 42 , the indoor fan will run at low speed, and after one minute, the indoor fan
indoor amb. tube
~30˚C.
min.
i . n m i . n
preset wind min.
preset wind
Stop
30s
7min
60s
15s
3min Set fan speed
Stop
and the indoor fan is at stop state, the indoor fan will begin to run at low
40 , the indoor fan also will run at low speed; and after
tube
42 , the fan will run at present speed.
Stop heating
Original operating status
Start heating
42 , the indoor fan will be converted
tube
27