Fujitsu AOTG30KMTC, Service Manual, Page: 150 / 199

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Flowchart
The defrost proceed by integrating operation time, outdoor temperature, and outdoor heat ex-
changer temperature as follows.
Compressor OFF
Outdoor fan motor OFF
30 sec later four - way valve OFF
35 sec later compressor ON (30)
36 sec later compressor ON (34)
(Not defrosted for 10 minutes)
Heating operation start : Compressor ON
Outdoor heat exchanger temperature:
Over +13 ° C (30)
+12 ° C (34)
or
Compressor ON time: Maximum 15 minutes
Defrost end
Compressor
integrating
operation:
Over 22 min.
Outdoor
heat exchanger
temperature:
Below - 9
° C
Outdoor
heat exchanger
temperature:
Below - 5
° C
Compressor
integrating
operation:
Over 35 min.
2nd and later defrost
Integrating defrost
(Constant monitoring)
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
Defrost start
Tn-Tn10 < - 5deg
Tn-Tnb < - 2deg
However, Tn ≤ -6
°C
(30)
(34)
Compressor
OFF count :
40 times
(Less than 10min.)
1st defrost
Compressor
integrating
operation:
Over 62 min. Compressor
integrating
operation:
Over 240 min.
Outdoor
heat exchanger
temperature:
Below - 3
° C
Compressor
integrating
operation:
Over 215 min.
Outdoor
heat exchanger
temperature:
Below - 5
° C
Tn ≤ -10 °C
- (04-18) -
6. Defrost operation control
CONTROL AND FUNCTIONS CONTROL AND FUNCTIONS