Hitachi RAS-(4-12)HNP(1)(E) - Pump down Refrigerant

3 Piping work and
refrigerant charge
88
SMGB0087 rev.0 - 12/2013

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.