Daikin VRV 5 RXYA8A7Y1B Installation And Operation Manual

Also see for VRV 5 RXYA10A7Y1B: Installer and user guide

15 Piping installationInstallation and operation manual34RYMA5+RXYA8~20A7Y1BVRV 5 heat pump4P739915-1 – 2023.12▪ Make sure that the total length of the piping connected to the jointis absolute straight for more than 500 mm. Only if a straight fieldpiping of more than 120 mm is connected, more than 500 mm ofstraight section can be ensured.>120 mm>500 mm15.2.7 To connect the refrigerant branching kitFor installation of the refrigerant branching kit, refer to the installationmanual delivered with the kit.▪ Mount the refnet joint so that it branches either horizontally orvertically.▪ Mount the refnet header so that it branches horizontally.AB±30° ab cdaa Horizontal surfaceb Refnet joint mounted verticallyc Refnet joint mounted horizontallyd Header15.3 Checking the refrigerant piping15.3.1 About checking the refrigerant pipingRefrigerant piping works arefinished?The indoor units / SV units /outdoor unit are alreadypowered ON?Use procedure:"Method 2: after power ON"Finish piping workUse procedure:"Method 1: Before power ON(regular method)"YesYesNoNoIt is very important that all refrigerant piping work is done before theunits (outdoor, SV unit or indoor) are powered on. When the unitsare powered on, the expansion valves will initialise. This means thatthe valves will close.NOTICELeak test and vacuum drying of field piping, SV units andindoor units is impossible when field expansion valves areclosed.Method 1: Before power ONIf the system has not yet been powered on, no special action isrequired to perform the leak test and the vacuum drying.Method 2: After power ONIf the system has already been powered on, activate setting [2‑21](refer to "18.1.4 To access mode 1 or 2" [4 46]). This setting willopen field expansion valves to guarantee a refrigerant pipingpathway and make it possible to perform the leak test and thevacuum drying.DANGER: RISK OF ELECTROCUTIONNOTICEMake sure that all indoor units and SV units connected tothe outdoor unit are powered on.NOTICEWait to apply setting [2‑21] until the outdoor unit hasfinished the initialisation.Leak test and vacuum dryingChecking the refrigerant piping involves:▪ Checking for any leakages in the refrigerant piping.▪ Performing vacuum drying to remove all moisture, air or nitrogenin the refrigerant piping.If there is a possibility of moisture being present in the refrigerantpiping (for example, water may have entered the piping), first carryout the vacuum drying procedure below until all moisture has beenremoved.All piping inside the unit has been factory tested for leaks.Only field installed refrigerant piping needs to be checked.Therefore, make sure that all the outdoor unit stop valves are firmlyclosed before performing leak test or vacuum drying.NOTICEMake sure that all (field supplied) field piping valves areOPEN (not outdoor unit stop valves!) before you start leaktest and vacuuming.For more information on the state of the valves, refer to"15.3.3 Checking refrigerant piping: Setup" [435].15.3.2 Checking refrigerant piping: GeneralguidelinesConnect the vacuum pump through a manifold to the service port ofall stop valves to increase efficiency (refer to "15.3.3 Checkingrefrigerant piping: Setup" [435]).NOTICEUse a 2-stage vacuum pump with a non-return valve or asolenoid valve that can evacuate to a gauge pressure of–100.7 kPa (−1.007 bar).NOTICEMake sure the pump oil does not flow oppositely into thesystem while the pump is not working.NOTICEDo NOT purge the air with refrigerants. Use a vacuumpump to evacuate the installation.