Daikin RR71B8V3B Installation Manual Download Page 8

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Installation manual

RR+RQ71+10 RR+RQ7 RR+RQ71~12

RR+RQ71B2W1B

Split System air conditioners

4PW23689-1C

Refrigerant pipe size

■

Pair system

(See figure 2)

■

Simultaneous operation system (twin: see

figure 3

, triple: see

figure 4

)

The pipes between the outdoor unit and the branch (L1) should have
the same size as the outdoor connections. The pipes between the
branch and the indoor units (L2~L4) should have the same size as
the indoor connections. Branch: see marking '

■

' on figures

Allowable pipe length and height difference

See the table below concerning lengths and heights. Refer to figures

. Assume that the longest line in the figure corresponds with the

actual longest pipe, and the highest unit in the figure corresponds
with the actual highest unit.

The minimal piping length should be 5 m. If installation is performed
with less field piping, the system will be overcharged (abnormal HP,
etc.). If the distance between indoor and outdoor unit is less than
5 m, please make sure that the piping length is

≥

5 m by additional

bending of the pipes.

RECAUTIONS

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).

■

In order to prevent dirt, liquid or dust from entering the piping,
cure the piping with a pinch or taping.

Great caution is needed when passing copper tubes through
walls.

■

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.

■

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 oil will cause compressor
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 color with the
circled color of the oil checking reference card.

- If oil color is identical to the circled color or darker, replace

the piping, install new piping or clean the piping thoroughly.

- If oil color 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 oxidized 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.

Refrigerant pipe size

Gas pipe