Pump Down (For Au*30/ 36/ 45/ 54Luas); Compressor Preheating - Fujitsu AU*24LUAR Service Instruction

5-15. PUMP DOWN ( For AU*30/ 36/ 45/ 54LUAS )
Perform the following procedures to collect the refrigerant when moving the indoor unit or the outdoor unit.
When the product is stopped:
1. Press the PUMP DOWN switch (SW2) on the outdoor unit.
(The LED on the outdoor unit circuit board flickers every 1second.)
2. The pump down operation (cooling operation) begins right away.
After operation starts, close the 3-way valve (liquid).
3. After 2-3minutes, operation stops. Close the 3-way valve (gas) within 1minute after operations stops.
4. The LED will go out 3minutes after it stops. Disconnect the power supply after confirming that the LED has gone out.
When the product is operating:
1. Press the PUMP DOWN switch (SW2) on the outdoor unit. The LED on the outdoor unit circuit board flickers
every 1second, and operation stops.
At this point, recovery has not been completed, so do not close the 2 and 3-way valves.
2. The pump down operation (cooling operation) begins after 3minutes.
Close the 3-way valve (liquid) after operation starts.
3. After 2-3minutes, operation stops. Close the 3-way valve (gas) within 1minute after operations stops.
4. The LED will go out 3minutes after it stops. Disconnect the power supply after confirming that the LED has gone out.

5-16. COMPRESSOR PREHEATING

When the outdoor heat exchanger temperature is lower than Operation temperature (Refer to Table 8) and the heating
operation has been stopped for 3 hours, power is applied to the compressor and the compressor is heated.
(By heating the compressor, warm air is quickly discharged when operation is started.)
When operation was started, and when the outdoor temperature rises to Release temperature or greater,
preheating is over.
(Table 8 : Preheating Operation / Release Temperature)
Before 24 hour
Operation Release
temperature temperature
3°C
After 24 hour
Operation
temperature
7°C 0°C
Release
temperature
4°C
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