Hitachi RAS-4-HNCE - General Notes before Performing Pipe Work; Piping Materials

3. Piping work and refrigerant charge
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SMGB0079 rev.0 - 01/2013
3.1 General notes before performing pipe work
3.1.1 Piping Materials
1 In order to avoid supply problems in terms of local regulations and quality, prepare locally-supplied copper pipes.
N O T E
IncaseofusingcopperpipesforpipingsectionsbiggerthanØ19.05mm(3/4inches),aringworkcannotbeper-
formed.Ifnecessary,useajointadapter.
2 Select the piping size with the correct thickness and correct material able to withstand sufcient pressure .
3 Select clean copper pipes. Make sure there is no dust and moisture inside. Blow the inside of the pipes through with
oxygen-free nitrogen to remove any dust and foreign materials before connecting pipes.
4 After connecting the refrigerant piping, seal the open space between the knockout hole and refrigerant pipes by using
insulation material as shown below:
A. Insulator material.
B. Field-supplied refrigeration pipe.
C A U T I O N
• Donotusesaws,grindstonesorothertoolswhichcause
copperpowder.
• Whencuttingpipes,securethepartforbrazinginaccord-
ancewithbothnationalandlocalregulations.
• Use security glasses and gloves for cutting or welding
works.

Piping Connection
When connecting liquid piping for units with piping longer than 15 meters, apply a piping size of Ø9.52 mm (3/8 inches). Fix
the connecting pipe as shown in the following gure using the insulation attached to the Indoor Unit.
A. Use the are nut of the indoor unit.
B. Insulate this part with the attached insulation.
C. Fix this part with the attached cord band or with tape.
D. Field-supplied refrigerant piping.
E. Field-supplied insulation.
F. Brazing.
G. Make ares after attaching are nut to the connecting pipe in
the Multi-kit package.
H. Insulation attached to indoor unit.
I. Indoor unit.
N O T E
• Asystemwithnomoistureoroilcontaminationwillgivemaximumperformanceandlifecyclecomparedtoa
poorlypreparedsystem.Takeparticularcaretoensurethatallcopperpipingiscleananddryinternally.
• Toensurethis,blowoxygen-freenitrogenthroughthepipes.