.REFRIGERANT PIPING WORK (5/5) )(PRECAUTIONS WHEN BRAZING THE REFRIGERANT PIPINGS) t reuse joint which have been. . used once already>• When brazing the refrigerant piping, carry out brazing work (NOTE 2) after substituting nitrogen for air(flow nitrogen into the piping and substitute nitrogen for air (NOTE 1) (see the drawing below)).NOTES1.The proper pressure for having nitrogen flow through the piping is approximately 0.02MPa, a pressure that makes onefeel like breeze and can be obtained through a pressure reducing valve.2.Do not use flux when brazing refrigerant piping. Use phosphorcopper brazing filler metal (BCuP-2:JIS Z 3264/B-Cu93P-710/795:IS0 3677)that does not require flux. (If chlorinated flux is used, Refrigerant pipingthe piping will be corroded and, in addition if fluorineis contained, the refrigerant oil will be deterioratedand the refrigerant circuit will be affected badly.)I(S) Do not use anti-oxidants when brazing the piping joints. ]Prohibited (Residue can clog pipes and break equipment.) sto valve.AIRTIGHTNESS TEST AND AIR-PURGE(AIRTIGHTNESS TEST )• Perform a refrigerant leakage check using nitrogen gas (airtightness test)with the outdoor unit stop valve close, to make sure there are no leakage.)• For the airtightness test, raise the pressure to the ________IOUTDOOR UNITIStop valvedesign pressure in the high pressure section (4.17 MPa) 'For the airtightness test, the unit passes the test ifthe pressure in the high pressure section does not drop 'iessurfor 24 hours after increasing to the design pressure. augeA correction is required since the pressure decreases 'LNitrog I Vacuum pumpI INDOOR UNIT I���������"E2::approx. 0.01Mpa when the ambient - - - - - - - 'temperature of 1°c decreases. (CHECKING LEAKAGE)• If the pressure drop is confirmed, perform the airtightness test again after checking and modifying the leakage points.(AIR-PURGE)• Evacuate by the vacuum pump for more than 2 hours until the internal pressure decreases below -0.1MP.After that, leave it with -0.1MPa or less for more than one hour and confirm that the value of vacuum gauges does not increase.• If the value of vacuum gauge increases, there is moisture inside the refrigerant piping or there are leakage points.Perform evacuation again after checking and improving the leakage points.NOTE• After doing an air-purge with a vacuum pump, the refrigerant pressure may not rise even if the stop valves are opened.This is because the refrigerant piping path is closed off by the outdoor unit electronic expansion valve, etc.There are no problems if the outdoor unit is running.-CHARGING THE REFRIGERANT (1/2) )< Be sure to useR32 as refrigerant.)/(7-1 PRECAUTIONS FOR ADDING REFRIGERANT )This unit does not require charging. So if the piping length is within the lengths shown in thetable below, no additional refrigerant needs to be charged.Liquid piping size Length for which additional In case where the piping length exceeds that shown in the left table orcharging is not required recharging needs to be performed, charge as described below.09.5mm x t 0.8mm 30m Be sure to write down the additional amount of refrigerant charged or theentire amount recharged on the indications label to the back side of the( 7.2 ADDING REFRIGERANT ) front plate, after the unit installed.From the table below, select a refrigerant amount that is suitable for a piping length exceeding the length forwhich charging is actually needed. Then add the refrigerant from the service port of the liquid side stop valve.Outdoor units Liquid Length for which Length of piping exceeding the length for which additional chargingadditional charging is not required, R32 additional amount (kg)type piping size is not required 30m or less 40m or less 50m or lessRZA24AVMKRZA30AVMK 09.5mm 30m� 0.25 0.50(Note) If the length of the refrigerant piping is within the range shown by 1222:J, additional charge is not required.(7.3 COMPLETE RECHARGING OF THE REFRIGERANT) (When recharging for compressor replacement, etc.)Recharge the amount of refrigerant selected from the table below.Outdoor units _L_iquid_ Piping length, R32 complete additional amount (kg}type piping size 10m or less 20m or less 30m or less 40m or less 50m or lessRZA125AV16 09.5mm 2.90 2.90 2.90 3.15 3.40RZA140AV16 09.5mm 2.90 2.90 2.90 3.15 3.40'---31'RZA125AV16RZA140AV16
