Refrigerant Pipe Size; Allowable Pipe Length And Height Difference; Guidelines For Necessity Of A Trap; Precautions On Refrigerant Piping - Rotex RRRQ011AAV1 Manual De Instalación

5.2. Refrigerant pipe size

The pipes between outdoor unit and indoor unit should have the
same size as the outdoor connections.
Gas pipe
Liquid pipe

5.3. Allowable pipe length and height difference

See the table below concerning lengths and heights. Refer to
figure 1. 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.
Allowable pipe length (m)
Maximum total one-way piping length
Maximum height between indoor and outdoor
Chargeless length
(a) Parenthesized figure represents the equivalent length.

5.4. Guidelines for necessity of a trap

Since there is fear of the oil held inside the riser piping flowing back
into the compressor when stopped and causing liquid compression
phenomenon, or cases of deterioration of oil return, it will be
necessary to provide a trap at an appropriate place in the riser gas
piping.
A B
E
C
D
A trap is not necessary when the outdoor unit is installed in a higher
position than the indoor unit.
Installation manual
8
Refrigerant pipe size (mm)
Ø15.9
Ø9.5
(a)
L 50 (95)
H 30
≤10
L
A Outdoor unit
B Indoor unit
C Gas piping
D Liquid piping
E Oiltrap
H Install trap at
each difference in
height of 10 m.
6. 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 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.
Installation period
More than a month
Less than a month
Regardless of the period
Great caution is needed when passing copper tubes through
walls.
■
For handling of stop valves, refer to "6.3. Guidelines for handling
stop valve" on page 9.
■
Only use the flare nuts included with the unit. Using different
flare nuts may cause the refrigerant to leak.
■
Ensure that the field piping and connections are not subjected to
stress.
■
Use appropriate fire resistant piping insulation according to
national regulations.

6.1. Guidelines 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
Protection method
Pinch the pipe
Pinch or tape the pipe
3 4 5
6
RRRQ011~016AAV1+Y1
Outdoor unit for air to water heat pump
4PW55782-1B