Precautions On Refrigerant Piping; Refrigerant Piping - Daikin REQ-BW1 Installation Manual

Refrigerant pipe size
Pair system (See figure 2)
Gas pipe
Class Standard size
71, 100, 125 Ø15.9
Allowable pipe length and height difference
See the table below concerning lengths and heights. Refer to
figure 2.
Allowable pipe length
Maximum allowable piping length (Parenthesized
figure represents equivalent length)
Maximum height between indoor and outdoor
Chargeless length
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.
P
RECAUTIONS 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 R-410A only when adding refrigerant
Installation tools:
Make sure to use installation tools (gauge manifold charge hose,
etc.) that are exclusively used for R-410A 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.
Place Installation period
More than a month
Outdoor unit
Less than a month
Regardless of the
Indoor
Great caution is needed when passing copper tubes through
walls.
Installation manual
5
Refrigerant pipe size
Size-up Liquid pipe
Ø19.1 Ø9.5
L1 50 m (70 m)
H1 30 m
≤7.5 m
L1
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

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.
R
EFRIGERANT PIPING
Field pipes can be installed in four directions.
1 2 3
4 4
Figure - Field pipes in four directions
1 Drill
2 Center area around knockout hole
3 Knockout hole
4 Slit
5 Connecting pipe
6 Bottom frame
7 Front plate
8 Pipe outlet plate
9 Screw front plate
10 Pipe outlet plate screw
A Forward
B Backward
C Sideways
D Downward
Cutting out the two slits makes it possible to install as shown in
the figure "Field pipes in four
(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
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.
7 8
9
5 6 10
A
D
directions".
6 mm drill. (See figure "Field
Ø
REQ71+100B7V3B + REQ71~125B7W1B
Split System air conditioners
4PW19495-1B
B
C