Precautions On Refrigerant Piping; Connecting The Refrigerant Piping; Caution For Brazing - Daikin RYYQ8T7Y1B Installation And Operation Manual

10. Precautions on refrigerant piping

Do not allow anything other than the designated refrigerant to

get mixed into the refrigerant cycle, such as air, nitrogen, etc. If
any refrigerant gas leaks while working on the unit, ventilate the
room thoroughly right away.
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).
Protection against contamination when installing pipes
Take measures to prevent foreign materials like moisture and
contamination from mixing into the system.
Installation period
More than a month
Less than a month
Regardless of the period
Block all gaps in the holes for passing out piping and wiring using
sealing material (field supply) (the capacity of the unit will drop and
small animals may enter the machine).
Example: passing piping out through the front.
1
Use clean pipes only.

 Hold the pipe end downwards when removing burrs.
Cover the pipe end when inserting it through a wall so that no

dust or dirt enters the pipe.
NOTICE
After all the piping has been connected, make sure there is
no gas leak. Use nitrogen to perform a gas leak detection.

10.1. Caution for brazing

Make sure to blow through with nitrogen when brazing. Blowing

through with nitrogen prevents the creation of large quantities of
oxidized film on the inside of the piping. An oxidized film
adversely affects valves and compressors in the refrigerating
system and prevents proper operation.
 The nitrogen pressure should be set to 0.02 MPa (i.e., just
enough so it can be felt on the skin) with a pressure-reducing
valve.
1 2
6
1 Refrigerant piping
2 Part to be brazed
3 Taping
4 Hands valve
5 Pressure-reducing valve
6 Nitrogen
Installation and operation manual
17
Protection method
Pinch the pipe
Pinch or tape the pipe
1 Close the areas marked with "
(When the piping is routed from the
front panel.)
3 4 5
6
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.

10.2. Connecting the refrigerant piping

NOTICE
Installation shall be done by an installer, the choice of
materials and installation shall comply with the applicable
legislation. In Europe, EN 378 is the applicable standard
that shall be used.
Ensure that the field piping and connections are not
subjected to stress.
10.2.1. Decide front or side (bottom) connection
Installation of refrigerant piping is possible as front connection or side
connection (when taken out from the bottom) as shown in the figure
below.
3
1 2
".
For side connections, the knockout hole on the bottom plate

should be removed:
1
3
NOTICE
Precautions when knocking out knockout holes:
Be sure to avoid damaging the casing.

After knocking out the knockout holes, we recommend

you remove the burrs and paint the edges and areas
around the edges using repair paint to prevent rusting.
When passing electrical wiring through the knockout

holes, wrap the wiring with protective tape to prevent
damage as shown above.
10.2.2. Remove the pinched pipes
WARNING
Any gas or oil remaining inside the stop valve may blow off
the pinched piping.
Failure to observe the instructions in procedure below
properly may result in property damage or personal injury,
which may be serious depending on the circumstances.
1 Left-side connection
2 Front connection
3 Right-side connection
1 Large knockout hole
2 Drill
2
3 Points for drilling
RYYQ+RYMQ+RXYQ8~20T7Y1B
VRV IV System Air Conditioner
4P329765-1 – 2012.09