Fujitsu R410A, Service Instruction

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3. Defrost Flow Chart
The defrosting shall proceed by the integrating operation time, outdoor temperature
and outdoor heat exchanger temperature as follows.
(Not defrosted for 10 minutes)
Heating operation start : Compressor ON
Outdoor heat exchanger temperature: Over 55° F(13°C)
or
Compressor ON time: Maximum 15 minutes
Defrost end
Compressor
integrating
operation:
Over 17 minutes Compressor
integrating
operation:
Over 57 minutes
Tn < 15.8°F(- 9°C)
Tn < 23°F(- 5°C)
Compressor
integrating
operation:
Over 35 minutes
2nd and later defrost
Compressor : OFF
Outdoor fan motor : OFF
30 sec later 4-way valve : OFF
35 sec later compressor : ON
Compressor
integrating
operation:
Over 210 minutes
Integrating defrost
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
Defrost start
Tn < 26.6°F(- 3°C)
(and after 30 minutes
in the 26.6°F(- 3°C))
Compressor
integrating
operation:
Over 210 minutes
Tn < 23°F(- 5°C)
Compressor
OFF count :
40 times
(Less than 10 minutes)
1st defrost
(and after 5 minutes
in the 23°F(- 5°C)) (and after 5 minutes
in the 23°F(- 5°C))
Integrating defrost
( OFF count defrost )
01-16
䐟
䐠
䐡
Tn < -77°F(-25°C)
(and after 5 minutes
in the 41°F(5°C))
Tn - Tn10 < -41°F(5°C)
( Tn < -42.8°F(6°C))
=
Tn - Tnb < -35.6°F(2°C)
( Tn < -42.8°F(6°C))
=
=
=
Ta - Tn > 41°F(5°C)
=
=
Tn10 : Temperature of continuous operation at 10 minutes.
Tnb : Back 5 minutes temperature.
Tn : Outdoor heat exchanger temperature.
Ta : Outdoor temperature.
and
=