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6.
REFRIGERANT PIPING
NOTE
• All field piping must be installed by a licensed refrigeration technician
and must comply with relevant local and national regulations.
• After piping work is complete, do not under any circumstances open
the shutoff valve until "7. FIELD WIRING" and "10. CHECKING OF
DEVICE AND INSTALLATION CONDITIONS" are complete.
• Do not use flux when brazing the refrigerant piping. Use the phosphor
copper brazing filler metal (B-Cu93P-710/795 : ISO 3677) which does
not require flux.
(Flux has extremely negative effect on refrigerant piping systems. For
instance, if the chlorine based flux is used, it will cause pipe corrosion or,
in particular, if the flux contains fluorine, it will damage the refrigerant oil.)
6-1 Selection of piping material and Refrigerant
branching kit
• Use only pipes which are clean inside and outside and which do not
accumulate harmful sulfur, oxidants, dirt, cutting oils, moisture, or
other contamination. (Foreign materials inside pipes including oils
for fabrication must be 9 mg/10 ft or less.)
• Use the following items for the refrigerant piping.
Material : Jointless phosphor-deoxidized copper pipe
Size : See "6-5 Example of connection" to determine the cor-
rect size.
Thickness : Select a thickness for the refrigerant piping which
complies with national and local laws.
• For piping work, follow the maximum tolerated length, difference in
height, and length after a branch indicated in the "6-5 Example of
connection".
• Outside unit multi connection piping kit and refrigerant branching kit
(sold separately) are needed for connection of piping between out-
side units (in case of multi system) and piping branches.
Use only separately sold items selected specifically according to the
outside unit multi connection piping kit, the refrigerant branching kit
selection in the "6-5 Example of connection".
6-2 Protection against contamination
when installing pipes
Protect the piping to prevent moisture, dirt, dust, etc. from enter-
ing the piping.
Place
Installation period
More than a month
Outdoor
Less than a month
Indoor
Regardless of the period
NOTE
Exercise special caution to prevent dirt or dust when passing piping
through holes in walls and when passing pipe edges to the exterior.
6-3 Pipe connection
•
Be sure to perform nitrogen permutation or nitrogen blow when
brazing. (Refer to figure 8)
Brazing without performing nitrogen permutation or nitrogen blow
into the piping will create large quantities of oxidized film on the
inside of the pipes, adversely affecting valves and compressors in
the refrigerating system and preventing normal operation.
(Refer to figure 8)
1. Refrigerant pipe
2. Location to be brazed
3. Nitrogen
4. Taping
5. Handy valve
6. Regulator
•
The pressure regulator for the nitrogen released when doing the
brazing should be set to about 2.9 psi (Enough to feel a slight
breeze on your cheek).
5
6-4 Connecting the refrigerant piping
1.
Precautions when knocking out knock holes
• Open knock hole (large, small) in the base frame by drilling the 4
• Be sure to avoid damaging the casing.
• After knocking out the holes, we recommend you to remove any
• When passing electrical wiring through the knock holes, protect the wir-
2.
Protection method
Pinch the pipe
Pinch or tape the pipe
3.
• Figure 12-1, 2 shows the example of connecting refrigerant piping to
• The local inter unit piping next accesorry pipes are field supplyed.
• About the detail of connecting pipes between outside units on out-
NOTE
Do not use anti-oxidants when brazing the pipe joints.
Residue can clog pipes and break equipment.
Direction to bring out the pipes
The local inter unit piping can be connected either forward or to the
sides (taken out through the bottom) as shown in the figure 9.
When passing out through the bottom, use the knock hole in the bot-
tom frame.
(Refer to figure 9)
1. Left-side connection
2. Front connection
3. Right-side connection
concave around it with a φ1/4"-bit. (Refer to figure 10)
(Refer to figure 10)
1. Knock hole (large : for liquid pipe, gas pipe and low side
equalizer pipe)
2. Knock hole (small : for high side equalizer pipe)
3. Drill
4. Concave section (4 points)
burrs and paint them using the repair paint to prevent rusting.
ing with a conduit or bushings, making sure not to damage the wiring.
Removing Pinch Piping
•
When connecting refrigerant piping to an outside unit, remove the
pinch piping using the procedure in the figure 11.
(Refer to figure 11)
•
About handling of shutoff valves, refer to [Shutoff valve operation
procedure] in "11-1 Before working".
CAUTION
After removing the gass, remove the pinch piping.
Any gas remaining inside may blow off the pinch piping when you
dissolve the brazing, causing damage.
(Refer to figure 11)
1. Pich piping (4 pieces)
2. Do not remove the relay piping.
3. Pinch piping
4. Procedure 1 : Confirm the shutoff valve is closed.
5. Procedure 2 : Connect a charge hose to the service port of
shutoff valve and remove the gas in the pinch piping.
6. Procedure 3 : After removing the gas in the pinch piping, dis-
solve the brazing using a burner and remove the pinch piping.
Connecting refrigerant piping to outside units
outside units.
side unit multi system, refer to the "4. Precautions when connect-
ing piping between outside units" and the installation manual
attached to the outside unit multi connection piping kit.
(Refer to figure 12-1)
1. When connected to the front
2. When connected at lateral side (bottom)
3. Remove the shutoff valve cover to connect.
4. Remove the knock hole on the bottom frame and route the
piping under the bottom frame.
5. Liquid pipe shutoff valve
6. Low side equalizer pipe shutoff valve
7. Gas pipe shutoff valve
8. High side equalizer pipe shutoff valve
9. Brazing
10. Liquid side accessory pipe (1)
11. Low side equalizer accessory pipe (1)
12. Gas side accessory pipe (1)
English
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