Daikin VRV III Manual page 409

Installation
Refrigerant Piping work
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This shows the piping method between the outdoor unit and the BEV unit and the indoor unit. Select
the pipe size and refrigerant branch kit depending on how the piping will be laid.
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For refrigerant piping of outdoor units, see the installation manual attached to the outdoor unit.
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Execute heat insulation work completely on both sides of the gas piping and the liquid piping. Oth-
erwise, a water leakage can result sometimes.
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When using a heat pump, the temperature of the gas piping can reach up to approximately 120
use insulation which is sufficiently resistant
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Improve the insulation on the refrigerant piping depending on the installation environment.
If the insulation is not sufficient, condensation may form on the surface of the insulation.
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Before refrigerant piping work, check which type of refrigerant is used. Proper operation is not pos-
sible if the types of refrigerant are not the same.
CAUTION
• Use a pipe cutter and flare suitable for the type of refrigerant.
• Apply ester oil or ether oil around the flare section before connecting.
• To prevent dust, moisuture or other foreign matter from infiltrating the tube, either pinch the end or
cover it with tape.
• Do not allow anything other than the designated refrigerant to get mixed into the refrigerant circuit,
such as air, etc. If any refrigerant gas leaks while working on the unit, ventilate the room thoroughly
right away.
• The outdoor unit is charged with refrigerant.
• For the refrigerant piping and branching, follow the "piping connection procedure".
• Be sure to use both a spanner and torque wrench together, as shown in the drawing, when connecting or
disconnecting piping to/from the unit.
• Refer to the Table 1 for the dimensions of flare nut spaces.
• When connecting the flare nut, apply ether oil or ester oil only to inner side of the flare and initially
tighten by hand 3 or 4 turns before tightening firmly.
• Refer to the Table 1 to determine the proper tightening torque.
Table 1
Pipe size
φ 9.5 (3/8")
32.7 – 39.9N·m (333 – 407 kgf·cm)
φ 15.9 (5/8")
61.8 – 75.4N·m (630 – 770 kgf·cm)
NOTE
The flare nuts used must be those included with the main body.
CAUTION
Over-tightening may damage the flare and cause a refrigerant leakage.
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to install the unit without a torque wrench, you may fol-
low the installation method mentioned below.
When you keep on tightening the flare nut with a spanner, there is a point where the tightening torque sud-
denly increases. From that position, further tighten the flare nut the angle shown below:
Table 2
Pipe size
φ 9.5 (3/8")
φ15.9 (5/8")
404
Tightening torque Flare dimension A (mm)
12.8 – 13.2
19.3 – 19.7
Apply ester oil or ether oil only
to inner side of the flare.
Further tightening angle Recommended arm length of tool
60 to 90 degrees
30 to 60 degrees
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Flare shape
Torque wrench
Spanner
Piping union
Flare nut
Approx. 200mm
Approx. 300mm
: http://splitoff.ru/tehn-doc.html
ED34-862
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