Refrigerant Piping Work - Daikin FHQG71CVEB Installation Manual

6. REFRIGERANT PIPING WORK

〈For refrigerant piping of outdoor units, see the installation manual attached to the outdoor unit.〉
〈Execute heat insulation work completely on both sides of the gas piping and the liquid piping.
Otherwise, a water leakage can result sometimes.〉
(When using a heat pump, the temperature of the gas piping can reach up to approximately 120°C, so use
insulation which is sufficiently resistant.)
〈Also, in cases where the temperature and humidity of the refrigerant piping sections might exceed
30°C or RH80 %, reinforce the refrigerant insulation. (20 mm or thicker) Condensation may form on
the surface of the insulating material.〉
〈Before refrigerant piping work, check which type of R410A refrigerant is used. Proper operation is
not possible if the types of refrigerant are not the same.〉
CAUTION
• Use a pipe cutter and flare suitable for the type of R410A refrigerant.
• Apply ester oil or ether oil around the flare section before connecting.
• Make sure to use the flare nut provided with the main unit. Using other flare nuts may cause
refrigerant leakage.
• To prevent dust, moisture 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.
• Before performing refrigerant piping work, install the stay (rein-
forcing plate) used for packaging and transporting.
• The outdoor unit is charged with refrigerant.
• Be sure to use both a spanner and torque wrench together, as
shown in the drawing, when connecting or disconnecting pipes
to/from the unit. (Refer to Fig. 10)
• Refer to "Table 2" for the dimensions of flare nut spaces.
• When connecting the flare nut, coat the flare section (both
inside and outside) with ester oil or ether oil, rotate three or
four times first, then screw in. (Refer to Fig. 11)
CAUTION
• Overtightening may damage the flare and cause a refrigerant
leakage.
• Do not let oil get on the screw holders on the dressing board.
Oil can weaken the screw holders.
Table 2
Pipe size Tightening torque
φ9.5(3/8")
φ15.9(5/8")
CAUTION
Be careful not to damage the flare section.
• Refer to "Table 2" to determine the proper tightening torque.
English
Applicable model
32.7-39.9 N • m
61.8-75.4 N • m
Fig. 10
Torque wrench
Flare nut
Fig. 11
Ester oil or ether oil
Flare dimensions A (mm)
FHQG-CVEB
12.8 – 13.2
19.3 – 19.7
Piping union
Spanner
Flare
R0.4-0.8
9