Hitachi RAS-1.0PNNBDH1 Installation & Maintenance Manual page 10

Installation instructions
(6) After finishing connecting the refrigerant pipes, keep it warm with
the insulation material.
·For outdoor unit side, surely insulate every piping including valves.
·Cover piping joints with pipe cover.
·Using piping tape, apply taping starting from the entry of outdoor unit.
- Fix the end of piping tape with adhesive tape.
- When piping has to be arranged through above ceiling, closet or area
where temperature and humidity are high, wind additional commercially
sold insulation for prevention of condensation.
5. Air Tight Test
·Air Tight Check - Do use Nitrogen.
Connect the gauge manifold using charging hoses with a nitrogen
cylinder to the check joints of the liquid line and the gas line stop
valves.
Perform the air tight test.
Don't open the gas line stop valves.
Apply nitrogen gas pressure of 550 psig (3.8 MPa).
Check for any gas leakage at the flare nut connections, or brazed
parts by gas leak detector or foaming agent.
Gas pressure doesn't decrease, which is OK.
After the air tight test, release nitrogen gas.
6. Vacuum Pumping and Refrigerant Charge
·Vacuum Pumping
(1) Remove the service port cap of the stop valve on the gas pipe
side of the outdoor unit.
(2) Connect the manifold gauge and vacuum pump to the service port
of the stop valve on the gas pipe side of the outdoor unit.
(3) Run the vacuum pump. (Work for more than 15 minutes.)
(4) Check the vacuum with the gauge manifold valve, then close the
gauge manifold valve and stop the vacuum pump.
(5) Leave it as is for one or two minutes. Make sure that the pointer of
the manifold gauge remains in the same position. Confirm that the
pressure gauge shows -14.7psig (-0.101MPa or -760mmHg).
(6) Remove the manifold gauge quickly from the service port of the
stop valve.
(7) After refrigerant pipes are connected and evacuated, fully open
all stop valves on both sides of gas pipe and liquid pipe.
(8) Open adjusted valve to add refrigerant (the refrigerant is liquid).
(9) Tighten the cap to the service port .
(10) Retighten the cap.
(11) Leak test foam with halogen leak detector to check the flare nut
and brazing Carolina Department leaks. Use foam that does not
generate ammonia (NH3) in the reaction.
·An excess or a shortage of refrigerant is the main cause of trouble to the unit. Charge the correct quantity of
refrigerant according to the description in the manual.
·Check for refrigerant leakage in detail. If a large refrigerant leakage occurs, it will cause difficulty in breathing or
harmful gases would occur if a fire is being used in the room.
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危 险
CAUTION
8
Clamp (field-supplied) Insulation (field-supplied)
Piping insulation procedure
Procedure
Completion Applying
of Ref. Nitrogen
Piping Gas
Repairing
of Leakage
Part
Air Tight Procedure
Indoor unit
Outdoor unit
Pressure
gauge
Manifold
valve
Vacuum
pump
Refrigerant pipe
(field-supplied)
Insulation
( field-supplied )
Check of
Pressure Pass
Decrease
Charge hose
(for R410A)