Hitachi Set Free mini-HNRQ1 Series, Service Manual

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INSTALLATION
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Protect cables and refrigerant pipes from the edges of the holes with insulations and so on. (Field supplied).
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Prevent the cables from contacting the refrigerant piping and the hot components of the unit directly.
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For the right side and rear side piping work, secure enough space for the piping.
(4) Be sure to attach the piping cover to prevent rain water entering the unit. Completely seal the penetration
parts of the pipes with field-supplied insulation in order to prevent rain water entering the unit.
(5) Use a pipe bender or an elbow (field-supplied) for bending work while connecting pipes.
3.5 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 pressure 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 of 1.5 meters. Otherwise, the piping may be damaged.
(4) Securely insulate the gas piping side and liquid piping side individually.
(5) Connect the pressure 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 leakage, please solve it and repeat the air tight test.
(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.
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The air tight test should be performed on the gas stop valve and the liquid stop valve simultaneously.
Otherwise, the air tight test is invalid.
●
Use the pressure gauge and the charging hose for exclusive use of R410A.
NOTICE
Piping Clamp
Gas Piping
Liquid Piping
Note:
Due to gas and liquid piping will stretch or contact at
different rates due to changing refrigerant temperatures.
Do not fasten gas and liquid piping together.
Distortion and deformation of the piping
can occur.
Procedure
Completion of Applying Check of
Pass
Ref. Piping Nitrogen Gas Pressure Decrease
Repairing of
Leakage Part
CAUTION
!