Pump Down Refrigerant - Hitachi RAS-5HVRNM1E Service Manual

3 Piping work and
refrigerant charge

3.2.8 Pump down refrigerant

When the refrigerant should be collected into the outdoor unit due to indoor/outdoor unit relocation, collect the refrigerant
as follows:
1 Attach the manifold gauge to the gas stop valve and the liquid stop valve.
2 Turn ON the power source.
3 Set the DSW1-1 pin of the outdoor unit PCB at the "ON" side for cooling operation. Close the liquid stop valve and collect
the refrigerant.
4 When the pressure at lower pressure side (gas stop valve) indicates -0.01 MPa (-100 mmHg), perform the following
procedures immediately.
• Close the gas stop valve.
• Set the DSW1-1 pin at the "OFF" side (To stop the unit operation).
5 Turn OFF the power source.
C A U T I O N
Measure the low pressure by the pressure gauge and keep it in a measurement higher than -0.01 MPa. If the
pressure is lower than -0.01 MPa, the compressor may be faulty.
59
SMGB0060 rev. 1- 12/2010
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