Fujitsu AOU18RLXFZH - Various Protections

26. VARIOUS PROTECTIONS
1. DISCHARGE GAS TEMPERATURE OVER RISE PREVENTION CONTROL
The discharge gas thermosensor (discharge thermistor : Outdoor side) will detect discharge gas
temperature.
When the discharge temperature becomes higher than Temperature , the compressor frequency
is decreased 20rps(AOU18RLXFZH) or 10rps(AOU24RLXFZH), and it continues to decrease the
frequency for 20rps(AOU18RLXFZH) or 10rps(AOU24RLXFZH) every 120 seconds until the
temperature becomes lower than Temperature .
When the discharge temperature becomes lower than Temperature ,the control of the compressor
frequency is released.
When the discharge temperature becomes higher than Temperature ,the compressor stops.
2. CURRENT RELEASE CONTROL
The compressor frequency is controlled so that the outdoor unit input current does not exceeds
the current limit value that was set up with the outdoor temperature.
The compressor frequency returns to the designated frequency of the indoor unit at the time
when the frequency becomes lower than the release value.
3. ANTI-FREEZING CONTROL (Cooling / Dry mode)
When the indoor unit heat exchanger and 2-way valve temperature becomes lower than Temperature ,
the compressor frequencyis decreased 10rps, and it continues to decrease the
frequency for 10rps every 120 seconds until the temperature becomes higher thanTemperature .
This operation is not released until both the temperature of the indoor unit heat exchanger and
2-way valve temperature exceed the release temperature.
( Table 20 : Anti-freezing protection operation / Release temperature )
AOU18RLXFZH
AOU24RLXFZH
219°F (104°C) 214°F (101°C) 230°F (110°C)
Temperature
Temperature Temperature
53.6°F(12°C)
37.4°F(3°C) 35.6°F(2°C) 42.8°F(6°C)
Temperature
Temperature
37.4°F(3°C) 35.6°F(2°C) 55.4°F(13°C)
Outside air
Temperature
Indoor Heat Ex.
Temperature
2-way valve
Temperature
Indoor Heat Ex.
Temperature
2-way valve
Temperature
53.6°F(12°C)
41.0°F(5°C)
53.6°F(12°C)
( Table 19 : Discharge temperature over rise prevension control / Release temperature )
=
>
<
01-27
4. COOLING PRESSURE OVER RISE PROTECTION
When the outdoor unit heat exchange sensor temperature rises to 154.4 °F (68 °C) or greater,
the compressor is stopped and error display is indicated.