Air Tight Test - Hitachi RAS-3.0HNSKQ Original Instruction

(4)Be sure to attach the piping cover to prevent rain water from going into the unit. Completely seal the
penetration parts of the pipes with field-supplied insulation in order to prevent rain water from going into the unit.
(5)Use a pipe bender or an elbow (field-supplied) for bending work while connecting pipes.

4.5 Air Tight Test

(1)The stop valves should be closed completely (factory-setting). Do not open the stop valves until all the
refrigerant piping connections, air tight test, and vacuum have been completed.
(2) The refrigerant used for the outdoor unit is R410A. Use the manifold gauge and the charging hose for
exclusive use of R410A.
(3) Connect the indoor/outdoor units with refrigerant piping. Mounted the piping to a stable wall or ceiling
with the piping clamp at interval 1.5 meters. Otherwise, the piping may be damaged.
(4) Securely insulate the gas piping and liquid piping separately.
(5) Connect the manifold gauge and the charging hoses to the check joints of the stop valves with a
nitrogen tank. Perform the air tight test at 4.15 MPa for the test pressure.
(6) For the air tight test, please use a leak detector or forming agent to detect the joints and stop valves for
the piping connection. If there is a leakage, please repair it and repeat the air tight test operation.
(7) If there is no leakage, the nitrogen gas should be discharged from the refrigerant pipes and the air tight
test is finished.
(8) Make sure to insulate the joints for the piping connection as well. Seal the gap between the piping
cover and pipes with the field-supplied packing after insulation work is completed.
The air tight test should be performed on the gas stop valve and the liquid stop valve simultaneously.
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Otherwise, the air tight test is invalid.
Use the pressure gauge and the charging hose for exclusive use of R410A.
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