Daikin VRV 5 RXYA8A7Y1B, Инструкция по установке и эксплуатации

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18 | Piping installation
Installer and user reference guide
108
RYMA5+RXYA8~20A7Y1B
VRV 5 heat pump
4P749918-1 – 2023.12
18.2.8 To braze the pipe end
NOTICE
Precautions when connecting field piping. Add brazing material as shown in the
figure.
1
1
1
1
2 2
≤Ø25.4 >Ø25.4
▪ When brazing, blow through with nitrogen to prevent creation of large quantities
of oxidised film on the inside of the piping. This film adversely affects valves and
compressors in the refrigerating system and prevents proper operation.
▪ Set the nitrogen pressure to 20 kPa (0.2 bar) (just enough so it can be felt on the
skin) with a pressure-reducing valve.
a b c d e
f
f
a Refrigerant piping
b Part to be brazed
c Taping
d Manual valve
e Pressure-reducing valve
f Nitrogen
▪ Do NOT use anti-oxidants when brazing pipe joints. Residue can clog pipes and
break equipment.
▪ Do NOT use flux when brazing copper-to-copper refrigerant piping. Use phosphor
copper brazing filler alloy (BCuP), which does NOT require flux.
Flux has an extremely harmful influence on refrigerant piping systems. For
instance, if chlorine based flux is used, it will cause pipe corrosion or, in
particular, if the flux contains fluorine, it will deteriorate the refrigerant oil.
▪ ALWAYS protect the surrounding surfaces (e.g. insulation foam) from heat when
brazing.
18.2.9 To connect the refrigerant piping to the outdoor unit
INFORMATION
All local inter unit piping are field supplied except the accessory pipes.