Daikin FNA25A2VEB Installer's Reference Manual

Also see for FNA25A2VEB: Installation manual Operation manual Installer's reference guide

Contents

6 InstallationInstaller reference guide15FNA25~60A2VEBSplit system air conditioners4P482940-1 – 2017.06▪ Always use 2 wrenches together when loosening a flare nut.▪ Always use a spanner and torque wrench together to tighten theflare nut when connecting the piping. This to prevent nut crackingand leaks.a bcda Torque wrenchb Spannerc Piping uniond Flare nutPiping size(mm)Tighteningtorque (N•m)Flaredimensions (A)(mm)Flare shape(mm)Ø6.4 15~17 8.7~9.1R=0.4~0.845°±290°±2AØ9.5 33~39 12.8~13.2Ø12.7 50~60 16.2~16.66.3.4 Pipe bending guidelinesUse a pipe bender for bending. All pipe bends should be as gentleas possible (bending radius should be 30~40 mm or larger).6.3.5 To flare the pipe endCAUTION▪ Incomplete flaring may cause refrigerant gas leakage.▪ Do NOT re-use flares. Use new flares to preventrefrigerant gas leakage.▪ Use flare nuts that are included with the unit. Usingdifferent flare nuts may cause refrigerant gas leakage.1 Cut the pipe end with a pipe cutter.2 Remove burrs with the cut surface facing down so that thechips do not enter the pipe.a ba Cut exactly at right angles.b Remove burrs.3 Remove the flare nut from the stop valve and put the flare nuton the pipe.4 Flare the pipe. Set exactly at the position as shown in thefollowing illustration.AFlare tool forR410A or R32(clutch type)Conventional flare toolClutch type(Ridgid-type)Wing nut type(Imperial-type)A 0~0.5 mm 1.0~1.5 mm 1.5~2.0 mm5 Check that the flaring is properly made.a bca Flare’s inner surface must be flawless.b The pipe end must be evenly flared in a perfect circle.c Make sure the flare nut is fitted.6.3.6 To braze the pipe endThe indoor unit and outdoor unit have flare connections. Connectboth ends without brazing. If brazing should be needed, take thefollowing into account:▪ When brazing, blow through with nitrogen to prevent creation oflarge quantities of oxidised film on the inside of the piping. Thisfilm adversely affects valves and compressors in the refrigeratingsystem and prevents proper operation.▪ Set the nitrogen pressure to 20 kPa (0.2 bar) (just enough so itcan be felt on the skin) with a pressure-reducing valve.a b c d effa Refrigerant pipingb Part to be brazedc Tapingd Manual valvee Pressure-reducing valvef Nitrogen▪ Do NOT use anti-oxidants when brazing pipe joints.Residue can clog pipes and break equipment.▪ Do NOT use flux when brazing copper-to-copper refrigerantpiping. Use phosphor copper brazing filler alloy (BCuP), whichdoes not require flux.Flux has an extremely harmful influence on refrigerant pipingsystems. For instance, if chlorine based flux is used, it will causepipe corrosion or, in particular, if the flux contains fluorine, it willdeteriorate the refrigerant oil.6.3.7 To connect the refrigerant piping to theindoor unitWARNING: FLAMMABLE MATERIALThe R32 refrigerant (if applicable) in this unit is mildlyflammable.1▪ Pipe length. Keep refrigerant piping as short as possible.▪ Flare connections. Connect refrigerant piping to the unit usingflare connections.▪ Insulation. Insulate the refrigerant piping on the indoor unit asfollows:A Ba dc e fb b a dc e fb b243 g 1 23 4gAB1A Gas pipingB Liquid pipinga Insulation material (field supply)b Cable tie (accessory)(1) Only for units using R32 refrigerant. Refer to the outdoor unit specifications for the type of refrigerant to be used.