8.
R
EFRIGERANT PIPE SIZE AND ALLOWABLE
PIPE LENGTH
DANGER
■
Piping and other pressure containing parts shall
comply with the applicable legislation and shall be
suitable
for
refrigerant.
deoxidised seamless copper for refrigerant.
■
Installation shall be done by an installer, the choice of
materials and installation shall comply with applicable
legislation. In Europe the EN378 is the application
standard that shall be used.
NOTICE
To persons in charge of piping work:
Be sure to open the stop valve after piping installing and
vacuming is complete. (Running the system with the valve
closed may break the compressor.)
INFORMATION
It is forbidden to discharge refrigerant into the atmosphere.
Collect the refrigerant in accordance with the freon
collection and destruction law.
8.1. Selection of piping material
■
Construction material: phosphoric acid deoxidised seamless
copper for refrigerant.
■
Temper grade: use piping with temper grade in function of the
pipe diameter as listed in table below.
■
The pipe thickness of the refrigerant piping should comply with
applicable legislation. The minimal pipe thickness for R410A
piping must be in accordance with the table below.
Temper grade
Pipe Ø
of piping material
6.4
O
15.9
O
O=Annealed
8.2. Refrigerant pipe size
The pipes between outdoor unit and indoor unit should have the
same size as the outdoor connections.
Gas pipe
Liquid pipe
Installation manual
9
Use
phosphoric
acid
Minimal thickness t (mm)
0.80
1.00
Refrigerant pipe size (mm)
Ø15.9
Ø6.4
8.3. Allowable pipe length and height difference
See the figure and table below concerning allowable lengths and
heights. 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.
L
H Height
L Length
Allowable pipe length
Maximum total one-way piping length
L
Minimum one-way piping length
L
Maximum height between indoor and outdoor
H
Chargeless length
L
9.
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.
Great caution is needed when passing copper tubes through
walls.
Place
Installation period
More than a month
Outdoor unit
Less than a month
Regardless of the
Indoor unit
■
Piping should be mounted so that the flare is not subjected to
mechanical stress.
30 m
3 m
20 m
≤10 m
Protection method
Pinch the pipe
Pinch or tape the pipe
period
RRLQ006~008BBV3
Outdoor unit for air to water heat pump
4PW68222-1 – 02.2011