Hitachi HSU-12RD03/R2(SDB) - Manual (Page 9)

Outdoor unit
5.Purging Method:To use vacuum pump
Detach the service port's cap of 3-way valve, the
valve rod's cap for 2-way valve and 3-way's, connect
the service port into the projection of charge hose
(Iow) for gaugemanifold. Then connect the projection
of charge hose (center) for gaugemanifold into
vacuum pump.
3-way valve
Gas Side
2-way valve
2-way valve
Service port cap
Gaugemanifold(for R410A)
Vacuum pump(for R410A)
Open
Close
Liquid Side
Open the handle at Iow in gaugemanifold, operate
vacuum pump. If the scale-moves of gause (Iow)
reach vacuum condition in a moment, check again.
Vacuumize for over 15min. And check the level gauge
which should read -0.1 MPa (-76 cm Hg) at Iow
pressure side. After the completion of vacuumizing,
close the handle 'Lo' in gaugemanifold and stop the
operation of the vacuum pump.
Check the condition of the scale and hold it for 1-2min.
If the scale-moves back in spite of tightening, make
flaring work again, the return to the beginning of .
Open the valve rod for the 2-way valve to an angle of
anticlockwise 90 degrees.
After 6 seconds, close the 2-way valve and make
the inspection of gas leakage.
No gas leakage?
In case of gas leakage, tighten
parts of pipe connection. If
leakage stops, then proceed
steps.
Detach the charge hose from the service port, open
2-way valve and 3-way. Turn the valve rod anticlockwise
until hitting lightly.
To prevent the gas leakage, turn the service port's
cap, the valve rod's cap for 2-way valve and 3-way's
a little more than the point where the torque increases
suddenly.
After attaching the each caps, check the gas leakage
around the caps.
CAUTION:
1.If the refrigerant of the air conditioner leaks, it is necessary to
discharge all the refrigerant. Vacuumize first, then charge the liquid
refrigerant into air conditioner according to the amount marked on
the name plate.
2.Please do not let other cooling medium, except specified one (R410A),
or air enter into the cooling circulation system. Otherwise, there will be
abnormal high pressure in the system to make it crack and lead to
personal injuries.
If it does not stop gas leakage, discharge
whole refrigerants from the service port.
After flaring work again and vacuumize,
fill up prescribed refrigerant from the gas
cylinder.
Anti countercurrent joint
3-way valve
2-way valve
7
6
6
6
1
2
3
1
3
4
5
6
7
8
3-way valve 2-way valve
3-way valve
2-way valve
Tube(for R410A)
3-way valve
Valve rod cap
Valve rod cap 7
7
Open
90 O
7