Fujitsu ASU7RLF1 Service Instructions Manual page 31

5. HIGH TEMPERATURE RELEASE CONTROL ( HEATING MODE )
On heating mode, the compressor frequency is controlled as following based on the
detection value of the indoor heat exchanger temperature sensor.
( Fig. 21 : Heating overload protection control )
AOU18RLXFZH
Indoor heat exchanger
temperature rises
Compressor is OFF
145.4°F(63°C)
The compressor frequency is
decreased 10rps every 20 seconds.
132.8°F(56°C)
The compressor frequency is
decreased 25rps every 120 seconds.
A°F(A°C)
The compressor frequency is
decreased 4rps every 120 seconds.
B°F(B°C)
Release
C°F(C°C)
heat exchange
Outdoor
tempreture
= < Th
12.2°F(-11°C)
= < Th<
8.6°F(-13°C) 12.2°F(-11°C)
= < Th<
5°F(-15°C) 8.6°F(-13°C)
= < Th<
-13°F(-25°C) 5°F(-15°C)
= < Th<
-20.2°F(-29°C) -13°F(-25°C)
-20.2°F(-29°C)
Th<
6. HIGH PRESSURE PROTECTION
(1).
When the pressure switch becomes OFF (Open : higher than 609.2 psi / 4.2 MPa),
the compressor is stopped.
It is released when the pressure switch becomes ON (Close : lower than 464.1 psi / 3.2 MPa)
after 3 minutes of compressor stop.
(2).
When the pressure switch is opened for 10 seconds from power on, all of outdoor unit operation is stopped.
The outdoor unit will start up if the pressure switch is returned to ON after 10 seconds has passed.
When 10 minutes (Cooling) or 3 minutes (Heating) has passed from the compressor stop and
pressure switch becomes ON, protection is released and the compressor will restart.
7. 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.
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Stable range
Release
In one operation of
the indoor unit : Qu air than
A°F B°F
(A°C) (B°C) (C°C)
125.6°F 125.6°F 122.0°F
(54°C) (52°C) (50°C)
129.2°F 125.6°F 118.4°F
(54°C) (52°C) (48°C)
125.6°F 122.0°F 114.8°F
(52°C) (50°C) (46°C)
122.0°F 118.4°F 111.2°F
(50°C) (48°C) (44°C)
113.0°F 109.4°F 102.2°F
(45°C) (43°C) (39°C)
104.0°F 100.4°F 93.2°F
(40°C) (38°C) (34°C)
Temperature
Temperature
226°F
176°F
(108°C)
(80°C)
01-28
Indoor heat exchanger
temperature rises
145.4°F(63°C)
The compressor frequency is
decreased 10rps every 20 seconds.
132.8°F(56°C)
The compressor frequency is
decreased 15rps every 120 seconds.
A°F(A°C)
The compressor frequency is
decreased 2rps every 120 seconds.
B°F(B°C)
Release
C°F(C°C)
All indoor unit opeate, : Qu air
C°F A°F B°F C°F
(A°C) (B°C) (C°C)
118.4°F 114.8°F 114.8°F
(50°C) (48°C) (46°C)
122.0°F 118.4°F 114.8°F
(50°C) (48°C) (46°C)
122.0°F 118.4°F 114.8°F
(50°C) (48°C) (46°C)
114.8°F 111.2°F 104.0°F
(46°C) (44°C) (40°C)
113.0°F 109.4°F 102.2°F
(45°C) (43°C) (39°C)
104.0°F 100.4°F 93.2°F
(40°C) (38°C) (34°C)
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Compressor is OFF
Stable range
Release
, the compressor is stopped.