Pump-Down Method; Precautions For Pump-Down; For Single Installation Of Outdoor Unit (Only One Outdoor Unit Installed); When Two Or More Outdoor Units Are Installed - Samsung AM009FN1DCH/AA Service Manual

7-2 Pump-down Method

7-2-1 Precautions for Pump-down

1. If the pressure is kept low for a long time to completely replenish the refrigerant of the pipe during the pump-down, then the
compressor may be damaged. Therefore, close the valve immediately if the pressure goes below 2kg/cm.g.
2. If the length of the pipe is too long or the outside temperature is too high, then it may not be able to pump down all of the refrigerant.
In this case, use an empty refrigerant container which can be used for recharge to place some of the system refrigerant inside the
container. The pump down can be easily carried out if only the remaining refrigerant is pumped down.
● Please use a rechargeable container for exclusive use when putting the refrigerant in the container.
Accidents such as explosions can happen and result in damage if normal refrigerant containers are used after illegal modification.

7-2-2 For Single Installation of Outdoor Unit (Only One Outdoor Unit Installed)

1. Close the liquid pipe SVC valve.
2. Press the K2 Button on the PCB of the main outdoor unit. ("K7" mark displayed on the outdoor unit PCB LED.)
3. Observe for low pressure by using the K4 button's view mode once the compressor starts operating.
(If the first number of the LED is "4, " then the following three digits represent the low pressure, expressed up to the first decimal
point.)
Example: 41 22 4 means the value of the low pressure, and 122 means that the low pressure is 12.2kg/cm,g.
4. If the low pressure goes below around 2kg/cm,g, then immediately close the SVC valve for the gas and finish the pump-down
operation.
(Finish the pump-down operation, press K2 button two more times, or reset the operation by pressing the K3 button once more.)

7-2-3 When Two or More Outdoor Units are Installed

1. Close the gas valves of each sub unit.
2. Press the K2 button of the outdoor unit PCB three times. At this time, K7 will be
displayed on the PCB LED. After pressing the button, wait for about 20~30 minutes
once the main unit compressor starts operating.
3. Close the liquid pipe valves of each sub unit.
4. Close the liquid pipe valves of the main unit, and observe for low pressure as in the case
of a single outdoor unit.
5. Close the gas valve of the main unit if the pressure drops down, and then finish the
pump-down operation mode.
Samsung Electronics
Gas pipe SVC valve is
Liquid pipe SVC
closed.
valve is closed.
Gas pipe SVC valve
Liquid pipe SVC
opened.
valve is opened.
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