Fujitsu ASU18RLF Service Instructions Manual page 36

4. HIGH TEMPERATURE RELEASE CONTROL ( Heating mode )
On heating mode, the compressor frequency is controlled as following based on the
detection value of the discharge pressure sensor.
( Fig. 23 : Heating overload protection control )
discharge pressure rises
The compressor frequency is
decreased 15rps every 120 seconds.
A psi ( A MPa )
The compressor frequency is
decreased 2rps every 120 seconds.
B psi ( B MPa )
Release
C psi ( C MPa )
5. HIGH PRESSURE PROTECTION
During the compressor operation, when detect the condition of the following table value,
the protection function will be worked.
The operation condition varies according to the compressor speed.
The protection function is, the compressor speed is descreased 7 rps every 60 seconds.
( Table 26 : Cooling operation )
Compressor frequency [ rps ]
rps < 20
=
20 < rps < 90
=
90 < rps < 100
=
( Table 27 : Heating operation )
Compressor frequency [ rps ]
rps < 20
=
20 < rps < 90
=
90 < rps < 100
=
100 < rps
Hp : detected discharge pressure sensor value
rps : detected compressor frequency
6. COMPRESSOR TEMPERATURE PROTECTION
Compressor temperature sensor is monitoring the compressor Temperature
When the compressor temperature sensor detects higher than Temperature
When 3 minutes has passed from the compressor stop and the compressor temperature sensor detects
lower than Temperature , protection is released and the compressor will restart.
( Table 28 : Operation value )
Temperature
AOU36RLXFZH
AOU45RLXFZ
8.6°F(-13°C) < Tn < 12.2°F(-11°C)
5°F(-15°C) < Tn < 8.6°F(-13°C)
-13°F(-25°C) < Tn < 5°F(-15°C)
Stable range
-20.2°F(-29°C) < Tn < -13°F(-25°C)
Release
Operation value [ psi (MPa) ]
Hp > 500.38 psi (3.45 MPa)
=
Hp > 551.14 psi (3.80 MPa)
=
Hp > 478.62 psi (3.30 MPa)
=
Operation value [ psi (MPa) ]
Hp > 500.38 psi (3.45 MPa)
=
Hp > 507.63 psi (3.50 MPa)
=
Hp > 478.62 psi (3.30 MPa)
=
Hp > 449.62 psi (3.10 MPa)
=
Temperature
226°F
176°F
(108°C)
(80°C)
01-33
Outdoor heat exchange
tempreture
=
=
=
=
Tn < -20.2°F(-29°C)
Release value [ psi (MPa) ]
Hp < 471.37 psi (3.25 MPa)
=
Hp < 522.14 psi (3.60 MPa)
=
Hp < 449.62 psi (3.10 MPa)
=
Release value [ psi (MPa) ]
Hp < 471.37 psi (3.25 MPa)
=
Hp < 478.62 psi (3.30 MPa)
=
Hp < 449.62 psi (3.10 MPa)
=
Hp < 420.61 psi (2.90 MPa)
=
, the compressor is stopped.
Dsicharge pressure [ psi (MPa) ]
A B C
478.62 psi 449.62 psi 406.11 psi
(3.30 MPa) (3.10 MPa) (2.80 MPa)
464.12 psi 478.62 psi 391.60 psi
(3.20 MPa) (3.00 MPa) (2.70 MPa)
435.11 psi 406.11 psi 377.10 psi
(3.00 MPa) (2.80 MPa) (2.60 MPa)
377.10 psi 362.59 psi 333.59 psi
(2.60 MPa) (2.50 MPa) (2.30 MPa)
333.59 psi 319.08 psi 290.08 psi
(2.30 MPa) (2.20 MPa) (2.00 MPa)