Fujitsu AS*G09KXCA Series Service Instruction page 21

3. Defrost Flow Chart
The defrosting shall proceed by the integrating operation time, outdoor temperature
and outdoor heat exchanger temperature as follows.
Normal defrost
Compressor
integrating
operation:
Over 40min.
Tn < - 17°C
=
Tn-Tn10 < - 5deg
Tn-Tnb < - 2deg
However, Tn < - 6 °C
=
Heating operation start : Compressor ON
Defrost start
Defrost Indicator:
[Operation indicator]
6sec. ON / 2sec. OFF
Outdoor heat exchanger temperature:
Over +16°C
or
Compressor ON time: Maximum 15min.
Defrost end
01-17
(Not defrosted for 10min.)
Integrating defrost
(Constant monitoring)
Compressor Compressor
OFF count : integrating
operation:
40 times
(Less than 10min.) Over 240min.
Outdoor
heat exchanger
temperature:
Below - 3°C
Compressor OFF
Outdoor fan motor OFF
50sec. later four - way valve OFF
55sec. later compressor ON
Compressor
integrating
operation:
Over 215min.
Outdoor
heat exchanger
temperature:
Below - 5°C