Panasonic EAIRC-MJ Series Installation Instructions Manual

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Panasonic EAIRC-MJ Series Installation Instructions Manual Manual pdf 18 page image

185. HOW TO PROCESS TUBINGThe liquid tubing side is connected by a flare nut, and the gastubing side is connected by brazing.5-1. Connecting the Refrigerant TubingUse of the Flaring MethodMany of conventional split system air conditioners employ theflaring method to connect refrigerant tubes that run betweenindoor and outdoor units. In this method, the copper tubes areflared at each end and connected with flare nuts.Flaring Procedure with a Flare Tool(1) Cut the copper tube to the required length with a tubecutter. It is recommended to cut approx. 30 – 50 cm longerthan the tubing length you estimate.(2) Remove burrs at each end of the copper tubing with atube reamer or file. This process is important and shouldbe done carefully to make a good flare. Be sure to keepany contaminants (moisture, dirt, metal filings, etc.) fromentering the tubing. (Figs. 5-1 and 5-2)AfterBeforeDeburringCoppertubingReamerFig. 5-1 Fig. 5-2NOTEWhen reaming, hold the tube end downward and be sure thatno copper scraps fall into the tube. (Fig. 5-2)(3) Remove the flare nut from the unit and be sure to mount iton the copper tube.(4) Make a flare at the end of the copper tube with a flare tool.(Fig. 5-3)Flare nutCoppertubingFlare toolFig. 5-3NOTEA good flare should have the following characteristics:● inside surface is glossy and smooth● edge is smooth● tapered sides are of uniform lengthCaution Before Connecting Tubes Tightly(1) Apply a sealing cap or water-proof tape to prevent dust orwater from entering the tubes before they are used.(2) Be sure to apply refrigerant lubricant (ether oil) to theinside of the flare nut before making piping connections.This is effective for reducing gas leaks. (Fig. 5-4)Apply refrigerant lubricant.Fig. 5-4(3) For proper connection, align the union tube and flare tubestraight with each other, then screw on the flare nut lightlyat first to obtain a smooth match. (Fig. 5-5)Flare nutUnionFig. 5-5● Adjust the shape of the liquid tube using a tube bender at theinstallation site and connect it to the liquid tubing side valveusing a flare.Cautions During Brazing● Replace air inside the tube with nitrogen gas to preventcopper oxide film from forming during the brazingprocess. (Oxygen, carbon dioxide and Freon are notacceptable.)● Do not allow the tubing to get too hot during brazing.The nitrogen gas inside the tubing may overheat,causing refrigerant system valves to become damaged.Therefore allow the tubing to cool 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 cause damage ormalfunctions.5-2. Connecting Tubing Between Indoor andOutdoor Units(1) Tightly connect the indoor-side refrigerant tubing extendedfrom the wall with the outdoor-side tubing.Indoor Unit Tubing Connection ( 1, 2... n-1)Indoor unit type 22 28 36 45 56 73 90 106 140 160Gas tubing (mm) ø12.7 ø15.88Liquid tubing (mm) ø6.35 ø9.52(2) To fasten the flare nuts, apply specified torque.● When removing the flare nuts from the tubing connections,or when tightening them after connecting the tubing, be sureto use 2 adjustable wrenches or spanners. (Fig. 5-6)If the flare nuts are over-tightened, the flare may be damaged,which could result in refrigerant leakage and cause injury orasphyxiation to room occupants.Outdoor unitTorque wrenchSpannerIndoor unitFig. 5-6