Fujitsu AB A30LBT Series Service Instruction page 29

3. ANTIFREEZING CONTROL (Cooling and Dry mode)
The compressor speed is decrease on cooling & dry mode when the indoor heat exchanger
temperature sensor detects the temperature lower than Temperature .
Then, the anti-freezing control is released when it becomes higher than Temperature
(Table 13 : Anti-freezing Protection Operation / Release Temperature)
Outdoor temperature
A zone
B zone
10°C
4. COOLING PRESSURE OVERRISE PROTECTION
When the outdoor unit heat exchange sensor temperature rises to 67°C or greater,
the compressor is stopped and trouble display is performed.After 3 minutes ST, release of protection.
5. HIGH TEMPERATURE RELEASE CONTROL ( HEATING MODE )
On heating mode, the compressor speed is controlled as following based on the
detection value of the indoor heat exchanger temperature sensor.
1. HIGH TEMPERATURE RELEASE CONTROL of Outdoor Unit
(Fig.12 : Heating Overload Protection Control)
Indoor heat exchange
temperature
The compressor speed is
decreased 3rps every 60seconds.
53°C
It returns to the normal operation
2. HIGH TEMPERATURE RELEASE CONTROL of Indoor Unit
(Fig.13 : Heating Overload Protection Control)
Indoor heat exchange
temperature
Refer to Table 14 below
55°C
It returns to the normal operation
(Table 14 : Compressor Operation)
Over than 54rps
Less than 54rps
Temperature
4°C
A zone
B zone
Speed down every 2minutes
OFF
Temperature
7°C
13°C
12°C
50°C
52°C
01-24
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