Field Piping and Wiring Si21-20536 Field Piping and WiringNot recommendable but in case of emergencyYou must use a torque wrench but if you are obliged to install the unit without a torque wrench,you may follow the installation method mentioned below.After the work is finished, make sure to check that there is no gas leak.When you keep on tightening the flare nut with a spanner, there is a point where the tighteningtorque suddenly increases. From that position, further tighten the flare nut the angle shownbelow:Caution CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING“Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazingfilter metal (BCuP) which does not require flux.”(Flux has extremely harmful influence on refrigerant piping systems. For instance, if the chlorinebased flux is used, it will cause pipe corrosion or, in particular, if the flux contains fluorine, it willdamage the refrigerant oil.)• Before brazing local refrigerant piping, nitrogen gas shall be blown through the piping toexpel air from the piping.If your brazing is done without nitrogen gas blowing, a large amount of oxide film developsinside the piping, and could cause system malfunction.• When brazing the refrigerant piping, only begin brazing after having carried out nitrogensubstitution or while inserting nitrogen into the refrigerant piping. Once this is done, connectthe indoor unit with a flared or a flanged connection.• Nitrogen should be set to 0.02 Mpa (0.2 kg/cm2) with a pressure-reducing valve if brazingwhile inserting nitrogen into the piping. (Refer to Fig.15)Pipe size Further tightening angle Recommended arm length of toolφ6.4 (1/4") 60 to 90 degrees Approx. 150mmφ9.5 (3/8") 60 to 90 degrees Approx. 200mmφ12.7 (1/2") 30 to 60 degrees Approx. 250mm
