Friedrich MW30C3F Installation Manual page 8

PUMP DOWN OPERATION (FORCED COOLING OPERATION)
To avoid discharging refrigerant into the atmosphere at the time of relocation or disposal, recover refrigerant by doing the cooling operation
or forced cooling operation according to the following procedure. (When the cooling operation cannot start in winter, and so on, start the
forced cooling operation.)
(1) Do the air purging of the charge hose by connecting the charging hose of gauge manifold to the charging port of 3 way valve (large) and
opening the low-pressure valve slightly.
(2) Close the valve stem of 3 way valve (small) completely.
(3) Start the cooling operation or following forced cooling operation.
When using the remote control unit
Press the TEST RUN button after starting the cooling operation by the remote control unit.
The operation indicator lamp and timer indicator lamp will begin to flash simultaneously during test run.
When using the MANUAL AUTO button of the indoor unit (The remote control unit is lost, and so on.)
Keep on pressing the MANUAL AUTO button of the indoor unit for more than 10 seconds.
(The forced cooling operation cannot start if the MANUAL AUTO button is not kept on pressing for more than 10 seconds.)
(4) Close the valve stem of 3 way valve (large) when the reading on the compound pressure gage becomes 0.05~0 MPa (0.5~0 kg/cm
(5) Stop the operation.
• Press the START/STOP button of the remote control unit to stop the operation.
• Press the MANUAL AUTO button when stopping the operation from indoor unit side.
(It is not necessary to press on keeping for more than 10 seconds.)
During the pump-down operation, make sure that the compressor is turned off before you remove the refrigerant piping.
Do not remove the connection pipe while the compressor is in operation 3 way valve open. This may cause abnormal pressure in the
refrigeration cycle that leads to breakage and even injury.
Install heat insulation around both the gas and liquid pipes. Failure to do so may cause water leaks.
Use heat insulation with heat resistance above 248 °F. (Reverse cycle model only)
In addition, if the humidity level at the installation location of the refrigerant piping is expected to exceed 70%, install heat insula-
tion around the refrigerant piping. If the expected humidity level is 70-80%, use heat insulation that is 15 mm or thicker and if the
expected humidity exceeds 80%, use heat insulation that is 20 mm or thicker.
If heat insulation is used that is not as thick as specified, condensation may form on the surface of the insulation.
In addition, use heat insulation with heat conductivity of 0.045 W/(m·K) or less (at 68 °F).
CAUTION
CAUTION
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