Daikin RXYQQ8T7Y1B Installation And Operation Manual

Contents

Installation and operation manual16 RXYQQ8~20T7Y1BVRV IV System Air Conditioner4P345099-1 – 2013.041 To indoor units2 Outdoor unit multi connecting piping kit (first branch)3 Outdoor unit multi connecting piping kit (second branch)10. Precautions on refrigerant piping Do not allow anything other than the designated refrigerant toget mixed into the refrigerant cycle, such as air, nitrogen, etc. Ifany refrigerant gas leaks while working on the unit, ventilate theroom thoroughly right away. When the design pressure for the existing field piping (gas andliquid piping) is at least 33 bar (3.3 MPa), then it is possible touse the existing piping (please read "9. Refrigerant pipe size andallowable pipe length" on page 11). Check also if the existingpiping (including branch piping) is compatible with the unit interms of materials and thickness and if the pipes and branchpiping are not corroded.If the existing field piping does not comply with the conditionsabove, replace the existing field piping with field piping whichmeets the specified conditions. Check if there was no compressor malfunction or similar issuesthat could contribute to piping problems in the past. If therewhere such problems, check that the appropriate repairs wheremade, and if not, implement such repairs. Use R410A only when adding refrigerant Installation tools:Make sure to use installation tools (gauge manifold, chargehose, etc.) that are exclusively used for R410A installations towithstand the pressure and to prevent foreign materials (e.g.,mineral oils and moisture) from mixing into the system. Vacuum pump:- Use a 2-stage vacuum pump with a non-return valve.- Make sure the pump oil does not flow oppositely into thesystem while the pump is not working.- Use a vacuum pump which can evacuate to –100.7 kPa(5 Torr, –755 mm Hg).Protection against contamination when installing pipesTake measures to prevent foreign materials like moisture andcontamination from mixing into the system.Block all gaps in the holes for passing out piping and wiring usingsealing material (field supply) (the capacity of the unit will drop andsmall animals may enter the machine).Example: passing piping out through the front. Use clean pipes only. Hold the pipe end downwards when removing burrs. Cover the pipe end when inserting it through a wall so that nodust or dirt enters the pipe.10.1. Caution for brazing Make sure to blow through with nitrogen when brazing. Blowingthrough with nitrogen prevents the creation of large quantities ofoxidized film on the inside of the piping. An oxidized filmadversely affects valves and compressors in the refrigeratingsystem and prevents proper operation. The nitrogen pressure should be set to 0.02 MPa (i.e., justenough so it can be felt on the skin) with a pressure-reducingvalve.1 Refrigerant piping2 Part to be brazed3 Taping4 Hands valve5 Pressure-reducing valve6 NitrogenDo not use anti-oxidants when brazing the pipe joints. Residue canclog 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.NOTICEThere are restrictions on the refrigerant pipe connectionorder between outdoor units during installation in case of amultiple outdoor unit system. Install according to followingrestrictions. The capacities of outdoor units A, B and Cmust fulfill the following restriction conditions: A≥B≥C.Installation period Protection methodMore than a month Pinch the pipeLess than a monthPinch or tape the pipeRegardless of the periodA B C1 2 3NOTICEAfter all the piping has been connected, make sure there isno gas leak. Use nitrogen to perform a gas leak detection.11 Close the areas marked with " ".(When the piping is routed from thefront panel.)1 2 3 4 566