Fujitsu ABHG54KRTA, Service Manual

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1-2. Heating operation
A sensor (room temperature thermistor) built in indoor unit body will usually perceive difference or
variation between setting temperature and present room temperature, and controls operation fre-
quency of compressor.
• If the room temperature is 6.0 °C lower than a set temperature, the compressor operation frequen-
cy will attain to maximum performance.
• If the room temperature is 1.0 °C higher than a set temperature, the compressor will be stopped.
• When the room temperature is within the range of +1.0°C to -6.0°C of the setting temperature, the
compressor frequency is controlled within the range shown below.
• Compressor frequency range
Unit: rps
Model name Minimum frequency Maximum frequency
ABHG54KRTA 17 120
1-3. Dry operation
The compressor rotation frequency shall change according to the temperature, set temperature, and
room temperature variation which the room temperature sensor of the indoor unit has detected as
shown in the table below.
Zone is defined by set temperature and room temperature.
• Compressor frequency range
Unit: rps
Model name Outdoor temperature zone Operating frequency
ABHG54KRTA
X zone 33
J zone 33
Y zone 0
• Compressor control based on room temperature
Ts+0.5°C
Ts -1.5 °C
Ts-0.5 °C
Ts+1.5 °C
X zone
J zone
Y zone
Room temperature drops
Room temperature rises
Ts: Set temperature
1-2. Heating operation
- (04-2) -
1. Compressor frequency control
CONTROL AND FUNCTIONS CONTROL AND FUNCTIONS