Panasonic R410A: 5/16 Installation Instructions Manual

Panasonic R410A: 5/16 Installation Instructions Manual Manual pdf 29 page image

29Caution Before Connecting Tubes Tightly(1) Apply a sealing cap or water-proof tape to prevent dustor water from entering the tubes before they are used.(2) Be sure to apply refrigerant lubricant to the matchingsurfaces of the flare and union before connecting themtogether. This is effective for reducing gas leaks.(Fig. 5-4)(3) For proper connection, align the union tube and flaretube straight with each other, then screw in the flare nutlightly at first to obtain a smooth match. (Fig. 5-5)● Adjust the shape of the liquid tube using a tube benderat the installation site and connect it to the liquid tubingside valve using a flare.Cautions During Brazing● Replace air inside the tube with nitrogen gas toprevent copper oxide film from forming during thebrazing process. (Oxygen, carbon dioxide and Freonare not acceptable.)● Do not allow the tubing to get too hot duringbrazing. The nitrogen gas inside the tubing mayoverheat, causing refrigerant system valves tobecome damaged. Therefore allow the tubing tocool when brazing.● Use a reducing valve for the nitrogen cylinder.● Do not use agents intended to prevent the formationof oxide film. These agents adversely affect therefrigerant and refrigerant oil, and may causedamage or malfunctions.5-2. Connecting Tubing Between Indoor andOutdoor Units(1) Tightly connect the indoor-side refrigerant tubingextended from the wall with the outdoor-side tubing.(2) To fasten the flare nuts, apply specified torque as atright:● When removing the flare nuts from the tubingconnections, or when tightening them after connectingthe tubing, be sure to use 2 adjustable wrenches orspanners as shown. (Fig. 5-6)If the flare nuts are over-tightened, the flare may bedamaged, which could result refrigerant leakage andcause in injury or asphyxiation to room occupants.● For the flare nuts at tubing connections, be sure to usethe flare nuts that were supplied with the unit, or elseflare nuts for R410A (type 2). The refrigerant tubing thatis used must be of the correct wall thickness as shown inthe table at right.Apply refrigerantlubricantFig. 5-4Flare nutUnionFig. 5-5Fig. 5-6Indoor unitOutdoor unitSpannerTorque wrencht1/32"(0.8 mm)t1/32"(0.8 mm)t1/32"(0.8 mm)t5/128"(1.0 mm)over t5/128"(over 1.0 mm)Tube diameterø1/4" (ø6.35 mm)ø3/8" (ø9.52 mm)ø1/2" (ø12.7 mm)ø5/8" (ø15.88 mm)ø3/4" (ø19.05 mm)Tightening torque,approximate120 – 160 lbs · in(140 – 180 kgf · cm)300 – 360 lbs · in(340 – 420 kgf · cm)430 – 480 lbs · in(490 – 550 kgf · cm)590 – 710 lbs · in(680 – 820 kgf · cm)870 – 1040 lbs · in(1000 – 1200 kgf · cm)Tube thicknessBecause the pressure is approximately 1.6 times higherthan conventional refrigerant pressure, the use of ordinaryflare nuts (type 1) or thin-walled tubes may result in tuberupture, injury, or asphyxiation caused by refrigerantleakage.● In order to prevent damage to the flare caused by over-tightening of the flare nuts, use the table above as a guidewhen tightening.● When tightening the flare nut on the liquid tube, use anadjustable wrench with a nominal handle length of 7-7/8".