Precautions On Refrigerant Piping; Flaring Guidelines - Daikin RZQG71L7V1B Installation Manual

9.

Precautions on refrigerant piping

Do not allow anything other than the designated refrigerant to

get mixed into the freezing cycle, such as air, 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).
During tests never pressurize the appliances with a pressure

higher than the maximum allowable pressure (see unit name
plate: PS).
In order to prevent dirt, liquid or dust from entering the piping,

cure the piping with a pinch or taping.
Place Installation period
More than a month
Outdoor unit
Less than a month
Regardless of the
Indoor unit
Great caution is needed when passing copper tubes through
walls.
Piping should be mounted so that the flare is not subjected to

mechanical stress.
 In case of simultaneous operating system
- Upward and downward piping should be performed at the
main piping line.
- Use branch piping kit (optional) for branching refrigerant
pipes.
Precautions to be taken. (For details, refer to the manual attached to
branch piping kit.)
- Install the branch pipes horizontally (with a maximum
inclination of 15°) or vertically.
- Length of branch pipe to the indoor unit should be as short as
possible.
- Try to keep lengths of both branch pipes to the indoor unit
equal.
Installation manual
9
Protection method
Pinch the pipe
Pinch or tape the pipe
period
When using existing refrigerant piping

Pay attention to the following points when using existing
refrigerant piping
 Perform a visual check on quality of residual oil in existing
refrigerant piping.
This check is extremely important because using existing
piping with deteriorated
breakdown.
- Put some residual oil of the pipes you want to reuse on a
piece of white paper or on the white surface of an oil
checking reference card and compare that oil colour with
the circled colour of the oil checking reference card.
- If oil colour is identical to the circled colour or darker,
replace the piping, install new piping or clean the piping
thoroughly.
- If oil colour is lighter, the pipes can be reused without
cleaning.
An oil checking reference card is indispensable for such
evaluation and can be obtained at your dealer.
 In the following situations, the existing piping should not be
re-used and new piping should be installed.
- If the previously used model had problems with its
compressor (this might cause oxidised coolant oil, scale
residue and other adverse effects).
- If the indoor or outdoor units were disconnected from the
piping for a long period of time (water or dirt might have
gotten into the piping).
- If copper piping is corroded.
 Flares should not be re-used but rather new ones made in
order to prevent leaks.
 Check welded connections for gas leaks, if the local piping
has welded connections.
 Replace deteriorated insulation with new material.
9.1.

Flaring guidelines

Flares should not be re-used. New ones should be made in

order to prevent leaks.
Use a pipe cutter and flare tool suitable for the refrigerant used.

Only use the flare nuts included with the unit. Using different

flare nuts may cause the refrigerant to leak.
Please refer to the table for flaring dimensions and tightening

torques (too much tightening will result in splitting the flare).
Piping size Tightening
(mm) torque (N•m)
Ø6.4 15~17
Ø9.5 33~39
Ø12.7 50~60
Ø15.9 63~75
Ø19.1 90~110
 When connecting the flare nut, coat the flare inner surface with
ether oil or with ester oil and initially tighten 3 or 4 turns by hand
before tightening firmly.
oil will cause compressor
Flare dimensions A Flare shape
(mm) (mm)
8.7~9.1
90 2
12.8~13.2
A
16.2~16.6
19.3~19.7
23.6~24.0
RZQG71~140L + RZQSG100~140L7V1+Y1B(9)
Split system air conditioners
4P327537-1 – 2012.08
R=0.4~0.8