Hitachi UTOPIA RASC Series Installation And Operation Manual page 35

REFRIGERANT PIPING &
REFRIGERANT CHARGE
Single system
¡
Calculate piping length AL(m)
RASC-5/10H(V)RNE
AL: Piping Length
l:
Charge-less piping length
(a): No additional charge is required AL≤
AL
(b): Additional charge is required AL≥
W (additional charge quantity) = (AL-
Indoor unit
Example:
−
AL: 45m
l: 30m
RASC-5HVRNE
RCI-5.0FSN2E
11.8. PUMP DOWN REFRIGERANT
When the refrigerant should be collected into the RASC unit due to
indoor/RASC 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 RASC 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.
l
l
l
) x p
W (additional charge quantity) = (45-30) x 0.06 = 0.9 kg
Twin system
¡
Calculate piping length AL(m) AL= A+B+C
RASC-5/10H(V)RNE
Indoor unit Indoor unit

CAUTION:
Measure the low pressure by the pressure gauge and keep it
not to decrease than -0.01 MPa. If the pressure is lower than
-0.01 MPa, the compressor may be faulty.
PMML0140A rev.1 - 07/2009
AL: A+B+C
l:
Charge-less piping length
W (additional charge
l
quantity) = (AL- ) x p
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