FXLQ20~6 FXNQ20~63P2VEB
VRV System air conditioners
4P323720-1 – 2012.06
Installation and operation manual
6
Cautions for brazing
Be sure to carry out a nitrogen blow when brazing.
Brazing without carrying out nitrogen replacement or releasing
nitrogen into the piping will create large quantities of oxidized
film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing normal
operation.
When brazing while inserting nitrogen into the piping, nitrogen
must be set to 0.02 MPa with a pressure-reducing valve (=just
enough so that it can be felt on the skin).
Do not use anti-oxidants when brazing the 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.
Use R410A only when adding refrigerant
Installation tools:
Make sure to use installation tools (gauge manifold charge hose,
etc.) that are exclusively used for R410A installations to
withstand 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 the system
while the pump is not working.
Use a vacuum pump which can evacuate to –100.7 kPa
(5 Torr, –755 mm Hg).
Drain piping work
Rig the drain pipe as shown below. Improperly rigged piping could
lead to leaks and eventually wet furniture and belongings.
1
Carry out the drain piping
Connect the drain hose (accessory part) using the attached
hose and parts, as shown in the figure below.
2
If converging multiple drain pipes, install according to the
procedure shown below. Use a slope downwards at a gradient of
at least 1/100.
Select converging drain pipes with a size that is suitable for the
operating capacity of the unit.
3
After piping work is finished, check if drainage flows smoothly.
Pour approximately 1 liter of water slowly in the air outlet and
check drainage flow.
4
Be sure to insulate all indoor pipes.
1
Refrigerant piping
2
Part to be brazed
3
Taping
4
Hands valve
5
Pressure-reducing valve
6
Nitrogen
1
2
3
4
5
6
6
1
Drip pan
2
Drain hose (accessory part)
3
Metal clamp (accessory part)
4
3/4" drain pipe
5
Cut to a suitable length
6
Slope
Drain piping connections
Do not connect the drain piping directly to sewage
pipes that smell of ammonia. The ammonia in the
sewage might enter the indoor unit through the drain
pipes and corrode the heat exchanger.
Keep in mind that the drain pipe will become blocked
if water remains in the drain pipe.
2
3
5
4
6
≥
1
/1
00
Piping process inside unit
≥
1/100
