Heat Controller VMH09SC-1 Service Manual page 26

Service Manual
After A/C starts up, the compressor will run at the Fmax frequency for 7 minutes according to outdoor
ambient temp. During the 7 minutes, frequency limitation is active.
7 minutes later, compressor running frequency will be controlled as below:
While
Temp. zone
Frequency
ΔT=32°F/0°C as default.
Note:
When T1-Ts stays in the same temp. zone for 3 minutes, the compressor will run as follows:
A~E: Increase the frequency to the higher level F10.
F: Keeps the current frequency.
G: Decreases the frequency to the lower level F1.
H: Runs at F1 for 1h. (If T1-Ts-ΔT >43°F/6°C, compressor will stop)
VMH SerieS
T1-Ts-ΔT
°F °C
41 (+5.0)
40 (+4.5)
38 (+3.5)
37 (+3.0)
37 (+2.5)
36 (+2.0)
35 (+1.5)
34 (+1.0)
33 (+0.5)
A B C
F10 F9 F8
D E
F7 F5
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Heat Controller, Inc.
F G
F3 F4