To Connect The Refrigerant Piping To The Indoor Unit - Daikin FXFN50A2VEB Installer And User Reference Manual

17 | Piping installation

17.2.4 To connect the refrigerant piping to the indoor unit

Installer and user reference guide
64
▪ 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
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 (CuP279, CuP281, or CuP284:DIN EN ISO 17672), which
does not require flux.
Flux has an extremely harmful influence on refrigerant piping systems. E.g., if a
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. using insulation foam) against heat
when brazing.
CAUTION
Install the refrigerant piping or components in a position where they are unlikely to
be exposed to any substance which may corrode components containing refrigerant,
unless the components are constructed of materials that are inherently resistant to
corrosion or are suitably protected against corrosion.
▪ Pipe length. Keep refrigerant piping as short as possible.
WARNING
▪
Use K65 piping for high-pressure applications with a working pressure of 120 bar
or 90 bar, depending on its location in the system.
▪
Use K65 unions and fittings approved for a working pressure of 120 bar or 90 bar,
depending on its location in the system.
▪
ONLY brazing is allowed for connection of pipes. No other types of connections
are allowed.
▪
Expanding of pipes is NOT allowed.
1 Insert the field pipe into the piping on the indoor unit side.
2 Connect refrigerant piping to the unit using only brazed connections.
NOTICE
When brazing, cover the plastic hold plate (d) and thermal insulation (e) by a wet
cloth and make sure the temperature does not exceed 200°C.
c d e
f
FXFN50~112A2VEB
CO₂ Conveni-Pack: indoor unit
4P677925-1 – 2021.07