Fujitsu AW*Z24LBC Service Instruction page 31

Defrost Flow Chart
The defrosting shall proceed by the integrating operation time and outdoor heat exchanger
temperature as follows.
(In case of 1st defrost)
Compressor integrating
Compressor integrating
operation:
operation:
Over 60 minutes to
Over 17 minutes to
below 240 minutes
below 60 minutes
Outdoor heat exchanger
Outdoor heat exchanger
temperature:
temperature:
Below -9°C Below -5°C
Heating operation start : Compressor ON
Compressor integrating
operation:
Over 240 minutes
Outdoor heat exchanger
temperature:
Below -3°C
Defrost start
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
Outdoor heat exchanger temperature:
Over 13°C
or
Compressor ON time:
Over 15 minutes
Defrost end
(Not defrosted for 10 minutes)
(In case of 2nd and later defrost)
Compressor integrating
operation:
Over 35 minutes to
below 240 minutes
Outdoor heat exchanger
temperature:
Below -6°C
Compressor OFF
Outdoor fan motor OFF
30 sec later four - way valve OFF
36 sec later compressor ON
05-17
Compressor integrating
operation:
Over 240 minutes
Outdoor heat exchanger
temperature:
Below -3°C