Panasonic U-5MX3XPQ Installation Manual

Contents

U-5~48MX3Urban Multi air conditioner4PW16235-1CInstallation manual96.4. Leak test and vacuum dryingThe units were checked for leaks by the manufacturer.Confirm that the valves are firmly closed before pressure test orvacuuming.Air tight test and vacuum drying■ Air tight test: Make sure to use nitrogen gas. (For the serviceport location, refer to the “Caution” label attached on the frontpanel of the outdoor unit.) (See figure 19)Pressurize the liquid and gas pipes (and oil equalizing pipe in case ofU-18~48MX3 type) to 3.8 MPa (38 bar) (do not pressurize more than3.8 MPa (38 bar)). If the pressure does not drop within 24 hours, thesystem passes the test. If the pressure drops, check where thenitrogen leaks from.■ Vacuum drying: Use a vacuum pump which can evacuate to–100.7 kPa (5 Torr, –755 mm Hg)1. Evacuate the system from the liquid and gas pipes (and oilequalizing pipe in case of U-18~48MX3 type) by using a vacuumpump for more than 2 hours and bring the system to –100.7 kPa.After keeping the system under that condition for more than 1 hour,check if the vacuum gauge rises or not. If it rises, the system mayeither contain moisture inside or have leaks.2. Following should be executed if there is a possibility of moistureremaining inside the pipe (if piping work is carried out during theraining season or over a long period of time, rainwater may enter thepipe during work).After evacuating the system for 2 hours, pressurize the system to0.05 MPa (vacuum break) with nitrogen gas and evacuate thesystem again using the vacuum pump for 1 hour to –100.7 kPa(vacuum drying). If the system cannot be evacuated to –100.7 kPawithin 2 hours, repeat the operation of vacuum break and vacuumdrying.Then, after leaving the system in vacuum for 1 hour, confirm that thevacuum gauge does not rise.Stop valve operation procedureIntroductionConfirm the sizes of the stop valves connected to the systemreferring to the table below.Opening stop valve1. Remove the cap and turn the valve counterclockwise with thehexagon wrench.2. Turn it until the shaft stops.Do not apply excessive force to the stop valve. Doing so may breakthe valve body, as the valve is not a backseat type. Always use thespecial tool.3. Make sure to tighten the cap securely.Closing stop valve1. Remove the cap and turn the valve clockwise with the hexagonwrench.2. Securely tighten the valve until the shaft contacts the main bodyseal.3. Make sure to tighten the cap securely.For the tightening torque, refer to the table below.(See figure 23)■ Always use a charge hose for service port connection.■ After tightening the cap, check that no refrigerant leaks arepresent.FLARE SHAPE and FLARENUT TIGHTENING TORQUE〈Precautions when connecting pipes〉■ See the following table for flare part machining dimensions.■ When connecting the flare nuts, apply refrigerant oil to the insideand outside of the flares and turn them three or four times at first.(Use ester oil or ether oil.)■ When loosening a flare nut, always use two wrenches incombination. When connecting the piping, always use a spannerand torque wrench in combination to tighten the flare nut.■ See the following table for tightening torque.(Applying too much torque may cause the flares to crack.)■ After all the piping has been connected, use nitrogen to performa gas leak check.1 Electric box lid2 Service precautionsLabel location3 CautionLabel locationNOTE Make sure to perform airtightness test and vacuumdrying using the service ports of the stop valve shownin the table below.U-5~16MX3 Liquid line stop valveGas line stop valveU-18~48MX3 Liquid line stop valveGas line stop valveOil-equalizing line stop valveU-5MX3 U-8MX3 U-10MX3 U-12MX3 U-14MX3 U-16MX3Liquid line stopvalve Ø9.5 Ø12.7Gas line stop valve Ø15.9 Ø22.2(*)(*) The model U-8MX3 supports on-site piping of Ø19.1 by the accessory pipes.Ø25.4(†)(†) The model U-12~16MX3 supports on-site piping of Ø28.6 by the accessorypipes.Tightening torque N•m (Turn clockwise to close)Stopvalvesize Shaft (valve body)Cap(valve lid)Serviceport Flare nutGas linepipingattachedto unitØ6.4 5.4~6.6 Hexagonalwrench4 mm13.5~16.511.5~13.914~17—Ø9.5 33~39Ø12.7 8.1~9.9 18~22 50~60Ø15.9 13.5~16.5Hexagonalwrench6 mm23~27 62~75Ø22.227~33Hexagonalwrench10 mm36~44 — 22~28Ø25.41 Service port2 Cap3 Hexagon hole4 Shaft5 SealPipe sizeTighteningTorque (N•m) A (mm) Flare shapeØ9.5 32.7~39.9 12.8~13.2Ø12.7 49.5~60.3 16.2~16.6Ø15.9 61.8~75.4 19.3~19.71 2 3 41 Piping union2 Spanner3 Flare nut4 Torque wrenchR=0.4~0.845 ±290 ±2A