Gree GWH09AB-A3DNA1B Service Manual page 22

Function and Control
Protection
Protection is the same as that under the cooling mode.
(3) Heating Mode
Working conditions and process of heating
If T Tpreset +35.6
amb.
will operate simultaneously, and the indoor fan will run at preset speed in the condition of preset cold air prevention.
If T T +41 ºF , the compressor will stop, the outdoor fan will stop with a time lag of 30s, and the indoor fan will stop after
amb. preset
60- second blow at low speed
ºF
If T +35.6 <T < T
preset amb.
Under this mode, the four-way valve is energized and temperature can be set within a range of 61 - 86 . The operating
symbol, the heating symbol and preset temperature are revealed on the display.
Condition and process of defrost
When duration of successive heating operation is more than 45 minutes, or accumulated heating time more than 90 minutes, and
one of the following conditions is reached, the unit will enter the defrost mode after 3 minutes.
ºF
a. T A , T
outdoor amb.
b. A T <B , T
ºF
outdoor amb.
c. B ºF T . <C , T
outdoor amb
ºF
d. T <C , T
outdoor amb. outdoor tube
At that time, the indoor fan stops and the compressor stops, and after 30 seconds the outer fan will stop, and then after 30
seconds, the four-way valve will stop. After 30 seconds, the compressor is initiated for raising the frequency to defrost frequency.
When the compressor has operated under defrost mode for 7.5 minutes, or T
operation. After 30 seconds, the compressor will stop. And after another 30 seconds, the four-way valve will be opened, and after
60 seconds, the compressor and the outer fan will be started, the indoor fan will run under preset cold air prevention conditions,
and H1 will be displayed at temperature display area on the display panel. Defrost frequency is 70Hz.
3.Protection
Cold air prevention
The unit is started under heating mode (the compressor is ON):
In the case of T
indoor amb.
a time lag of 2 minutes. Within 2 minutes, if T
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 >108 ºF
tube
In the case of T
indoor amb.
converted to preset speed. Within one-minute low speed operation, if T
Note: T indicated in
indoor amb.
command to start the compressor is performed according to the program, or after the unit is withdrawn from defrost, the
indoor ambient temperature before the defrost symbol is cleared.
Total current up and frequency down protection
If the total current I
total
will run at reduced frequency; and if I
(4) Fan Mode
Under the mode, the indoor fan will run at preset speed and the compressor, the outdoor fan, the four-way valve and the electric
heater will stop.
Under the mode, temperature can be set within a range of 61 - 86
(5) AUTO Mode
Working conditions and process of AUTO mode
Under AUTO mode, standard cooling temperature T
a. Once energized, if T
amb
and the run indicator will be bright; and if T
ºF , the unit enters heating mode, in which case the four-way valve, the compressor and the outdoor fan
+41 , the unit will maintain its original operating status. ºF
preset
ºF
W ;
outdoor tube
ºF X ;
ºF
outdoor tube
ºF
Y ºF ;
outdoor tube
Z
ºF
ºF
<75 : if T 104 and the indoor fan is at stop state, the indoor fan will begin to run at low speed with
ºF
tube
>104 , the indoor fan also will run at low speed; and after 1-minute operation at
tube
, the fan will run at present speed.
ºF
75 ºF : if T 108 , the indoor fan will run at low speed, and after one minute, the indoor fan will be
tube
and refers to, under initially heating mode, the indoor ambient temperature before the
W, frequency rise will be allowed; if I
Z, the compressor will stop and the outdoor fan will stop with a time lag of 30s.
total
68 ºF , the unit will be started under heating mode; if 68
77
amb
outer tube
ºF
>104 ºF
tube
X, frequency rise will not be allowed; if I
total
ºF
.
º F
is 77 and standard heating temperature T
preset
ºF
, the unit will be started under cooling mode.
19
E, the compressor will be converted to 53Hz
, the indoor fan will be converted to preset speed.
total
is 64
preset
ºF < T .< 77 , the unit will run under fanmode ºF
amb
ºF
Y, the compressor
ºF .