Carrier 42HVM109303 Service Manual page 31

If users switch on AC by remote controller, the compressor will run at the Fmax frequency for 7
minutes according to the outdoor ambient temp. During the 7 minutes, the frequency limitation is active.
7 minutes later, the compressor running frequency will be controlled as below:
While the zones of A,B,C... are corresponding to different compressor running frequency.
Note:
When T1-Ts keeps in the same temp. zone for 3 minutes, the compressor will run as the below rules:
A~E: Increase the frequency to the higher level until to F8.
F: Keep the current frequency.
G: Decrease the frequency to the lower level until to F1.
45
43
40
38
31.5
29.5
22
20
3.5
A
3.0
B
2.5
2.0
1.5
1.0
0.5
-0.5
-1.0
Fmax=F4
Fmax=F7
Fmax=F8
Fmax=F6
Fmax=F3
C
D
E
F
G
H
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