Pumping Down - Mitsubishi Electric SUZ-SWM40 Installationshandbuch

8. Pumping down

When relocating or disposing of the outdoor unit, pump down the system following
the procedure below so that no refrigerant is released into the atmosphere.
1 Turn OFF all the supply circuit (including Indoor unit, Heater, Outdoor unit etc.)
2 Connect the gauge manifold valve to the service port of the stop valve on the gas
pipe side of the outdoor unit.
3 Fully close the stop valve on the liquid pipe side of the outdoor unit.
4 Change the settings on the indoor unit.
• Set DIP switch SW1-3 to OFF, SW2-1 to OFF, SW2-4 to ON and SW6-3 to
OFF on the indoor control board.
• Disconnect the signal inputs IN1 (room thermostat 1 input), IN4 (Demand con-
trol input) and IN5 (Outdoor thermostat input).
IN1 IN4 IN5
5 Turn ON all the supply circuit.
6 From the main menu on the main controller of the indoor unit, select "Heating/
cooling mode" → "Cooling flow temp.".
7 From the main menu, select "Service" → "Operation settings" → "Freeze stat
function", and then set the minimum outdoor ambient temperature to *(asterisk).
You will be prompted to enter a password. THE FACTORY DEFAULT PASS-
WORD is "0000".
8 Perform the refrigerant collecting operation.
• Push "ON/OFF" button on the main controller.
• From the option menu, set "Cooling ON".
• Set the target flow temperature to 5 °C. If the system is controlled by a room
temperature thermostat, set the target room temperature to 10 °C.
Refrigerant collecting operation starts after 60 seconds.
• For details or for other information about the main controller settings, refer to
the installation manual or operation manual for indoor unit.
9 Fully close the stop valve on the gas pipe side of the outdoor unit when the pres-
sure gauge shows 0.05 to 0 MPa [Gauge] (approx. 0.5 to 0 kgf/cm
stop the outdoor unit.
• Push the "ON/OFF" button on the remote controller to stop the outdoor unit.
* Note that when the extension piping is very long with a large refrigerant
amount, it may not be possible to perform a pump down operation. In this case,
use refrigerant recovery equipment to collect all of the refrigerant in the system.
0 Set back the main controller setting changed at the procedure 8 above.
1 Push the "ON/OFF" button for about 3 seconds on the main controller of the in-
door unit to stop the unit.
2 Set back the main controller settings changed at any other procedure except 8.
3 Turn OFF all the supply circuit and set back the DIP switch settings on the indoor
circuit board as it were.
4 Remove the gauge manifold valve, and then disconnect the refrigerant pipes.
Warning:
When pumping down the refrigerant, stop the compressor before disconnect-
ing the refrigerant pipes.
• If the refrigerant pipes are disconnected while the compressor is operating
and the stop valve (ball valve) is open, the pressure in the refrigeration cycle
could become extremely high if air is drawn in, causing the pipes to burst,
personal injury, etc.
Caution:
Do NOT use this COOLING mode at any other cases except pumping down.
If it is used as normal operation, the heat pump may not provide enough per-
formance.
en
) and quickly
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