Fujitsu ASU 9RLF1 Service Instruction page 19

3. Defrost Flow Chart
The defrosting shall proceed by the integrating operation time, outdoor temperature
and outdoor heat exchanger temperature as follows.
Normal defrost
Outside air temp.
Outside air temp.
> -12.6°F(7°C)
< 14°F (-10°C)
=
Outdoor HEX temp. Outdoor HEX temp.
< 1.4°F(-17°C) < Outside air temp.
= =
or Outdoor HEX temp.
< -13°F (-25°C)
=
Heating operation start : Compressor ON
-4°F (-20°C)<
=
Outside air temp.
< -4°F(-20°C)
=
Outdoor HEX temp.
< Outside air temp.
=
-(12.6°F (7°C)) -(12.6°F (7°C))
or Outdoor HEX temp.
< -22°F(- 30°C)
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
Outdoor HEX temp.: Over 60.8°F(16°C)
Compressor ON time: Maximum 15 minutes
(Not defrosted for 10 minutes)
Intermittent operation
Compressor
OFF count :
40 times
(Less than 10min.)
Defrost start
Outdoor fan : OFF
Compressor speed : 0 rps
EEV : 480pulse
4-way valve : OFF
Compressor speed : 70rps (9/12RLFW1)
or
Defrost end
01-16
Integrating defrost
Continuous operation
Compressor Compressor
integrating integrating
operation: operation:
Over 240 min. Over 213 min.
Outdoor Outdoor
heat exchanger heat exchanger
temperature: temperature:
Below Below 23°F
26.6°F(- 3°C) (- 5°C)