Carrier 38QUA009DS, Service Manual, Page: 84 / 116

81
The indoor fan is controlled as below:
Setting fan
speed
Actual fan speed
H+(H+=H+G)
A H（=H）
B
C
M+(M+=M+Z)
D M(M=M)
E
F
L+(L+=L+D)
G L(L=L)
H
I
T1-Td
℃
(°F)
L
L-(L-=L-D)
H
H-（H-=H-G)
M
M-(M-=M-Z)
4.5(40.1)
3.0(37.4)
1.5(34.7)
4.5(40.1)
3.0(37.4)
1.5(34.7)
4.5(40.1)
3.0(37.4)
1.5(34.7)
Auto fan in cooling mode acts as follow:
a
b
c
d
6.0°C(42.8°F)
T1-Td
e
H
(H-L)*0.75+L
(H-L)*0.5+L
(H-L)*0.25+L
L
5.0°C(41.0°F)
4.0°C(39.2°F)
2.5°C(36.5°F)
1.0°C(33.8°F)
15.4.3 Heating Mode
15.4.3.1 Outdoor fan running rules
T4
E DC_FAN_SSLOW_SPD_ADD
D DC_FAN_SLOW_SPD_ADD
C DC_FAN_MIN_SPD_ADD
B DC_FAN_MID_SPD_ADD
A DC_FAN_HI_SPD_ADD
15
℃
(59°F)
13
℃
(55.4°F)
12
℃
(53.6°F)
10
℃
(50°F)
21
℃
(69.8°F)
19
℃
(66.2°F)
18
℃
(64.4°F)
16
℃
(60.8°F)
15.4.3.2 Indoor fan running rules
When the compressor is on, the indoor fan can
be set to high/med/low/auto. And the anti-cold
wind function has the priority.
The indoor fan is controlled as below:
Setting fan
speed
Actual fan speed
H
（
=H
）
H+(H+=H+G)
M(M=M)
M+(M+=M+Z)
L(L=L)
L+(L+=L+D)
H-
（
H-=H-G)
M-(M-=M-Z)
L-(L-=L-D)
T1-Td+1.5
℃
(34.7°F)
L
H
M
-1.5(29.3
°
F)
-3.0(26.6
°
F)
-4.5(23.9
°
F)
-
-1.5(29.3
°
F)
-3.0(26.6
°
F)
-4.5(23.9
°
F)
-1.5(29.3
°
F)
-3.0(26.6
°
F)
-4.5(23.9
°
F)
Auto fan action in heating mode:
0.0°C(32°F)
T1-Td+1.5°C(34.7°F)
L
(H+-L)*0.2+L
(H+-L)*0.4+L
(H+-L)*0.6+L
H+
(H+-L)*0.8+L
-1°C(30.2°F)
-2°C(28.4°F)
-3°C(26.6°F)
-4°C(24.8°F)
-5°C(23.0°F)
-6°C(21.2°F)
-6.5°C(20.3°F)
15.4.3.3 Defrosting mode
If any one of the following items is satisfied, AC
will enter the defrosting mode.
After the compressor starts up and keeps
running, mark the minimum value of T3 from
the 10th minutes to 15th minutes as T30.
1)If the compressor cumulate running time is up
to 29 minutes and T3< TCDI1, T3
＋
T30SUBT3ONE
≦
T30.
2)If the compressor cumulate running time is up
to 35 minutes and T3< TCDI2, T3
＋
T30SUBT3TWO
≦
T30.
3)If the compressor cumulate running time is up
to 29 minutes and T3< TCDI3 for 3 minutes.
4)If the compressor cumulate running time is up
to 120 minutes and T3<-15
℃
(5°F).
Condition of ending defrosting:
If any one of the following items is satisfied, the
defrosting will finish and the machine will turn to
normal heating mode.
----T3 rises to be higher than TCDE1.
----T3 keeps to be higher than TCDE2 for 80
seconds.
----The machine has run for 10 minutes in
defrosting mode.
Defrosting action
：
Compressor
Outdoor fan
4-Way valve
X1 10S
10S
no longer than 10min
X2