Carrier 42HVM109303 Service Manual page 35

While the zones of A,B,C... are corresponding to different compressor running frequency.
℃
ΔT=0 as default.
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 F10.
F: Keep the current frequency.
G: Decrease the frequency to the lower level until to F1.
H: Run at F1 for 1h.(if T1-Ts-ΔT >6 ,
Meanwhile, the compressor running frequency is limited by the current.
Off: Compressor stops.
Decrease: Decrease the running frequency to the lower level.
Hold: Keep the current frequency.
+5.0
+4.5
+3.5
+3.0
+2.5
+2.0
+1.5
+1.0
+0.5
℃ the compressor will stop)
I3HEAT
Decrease
I2HEAT
I1HEAT
Resume
H
G
F
E
D
C
B
A
Off
Hold
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