Fisher FSAI-Pro-91AE2 Service Manual page 37

Meanwhile, the maximum frequency is limited by the indoor fan speed.
Indoor fan speed
High speed/8 degree heating/ turbo function
Medium speed
Low speed/sleep mode
Silent mode
If users switch on AC by remote controller, the compressor will run at the Fmax frequency for 7
minutes according to 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.
Temperature compensation: ΔT=4°C as default (it can be modified by the service)
Note:
When T1-Ts keeps in the same temp. zone for 3 minutes, the compressor will run as the below rules:
A: Increase the frequency to 3 grade higher until to FREMAX.
B~E: Increase the frequency to 2 grade higher until to FREMAX.
F~G: Increase the frequency to 1 grade higher until to FREMAX.
H: Keep the current frequency.
I: Decrease the frequency to the 1 grade lower until to F1.
J: Run at F1 for 1h.(if T1-Ts-ΔT >2℃, the compressor will stop)
T1-Ts- T
+1.0
+0.5
+0.0
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0
-3.5
Maximum frequency
No limit
FHeatMaxMidFan
FHeatMaxLowFan
Fixed at F3
J
I
H
G
F
E
D
C
B
A
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