Daikin REQ71B8V3B Installation Manual Download

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Installation manual

REQ71+10 REQ7 REQ71~12 REQ71B2W1B

Split System air conditioners

4PW23690-1C

Refrigerant pipe size

Pair system

(See figure 2)

Allowable pipe length and height difference

See the table below concerning lengths and heights. Refer to

figure 2

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.

■

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.

EFRIGERANT

PIPING

■

Field pipes can be installed in four directions.

Figure - Field pipes in four directions

■

Cutting out the two slits makes it possible to install as shown in
the

figure "Field pipes in four directions"

(Use a metal saw to cut out the slits.)

■

To install the connecting pipe to the unit in a downward
direction, make a knockout hole by penetrating the center area
around the knockout hole using a

6 mm drill. (See

figure "Field

pipes in four directions"

■

After knocking out the knock-out, it is recommended to apply
repair paint to the edge and the surrounding end surfaces to
prevent rusting.

Refrigerant pipe size

Gas pipe

Class

Standard size

Size-up

Liquid pipe

71, 100, 125