Heat Insulation - Panasonic CU-YL28HBE5 Service Manual

2. CUTTING AND FLARING THE PIPING.
a. Please cut using pipe cutter and then remove the burrs.
b. Remove the burrs by using reamer. If burrs is not removed, gas leakage may be caused. Turn the piping end down to
avoid the metal powder entering the pipe.
c. Please make flare after inserting the flare nut onto the copper pipes.
3. Notes when connecting the refrigerant pipes.
• Use clean copper, pipes with no water or dust on the insides.
• Use phosphorus-free, unjointed copper pipes for the refrigerant pipes.
• If it is necessary to cut the refrigerant pipes, be sure to use a pipe cutter, and use compressed nitrogen or an air blower to
clean out any foreign particles from inside the pipe.
• Be careful not to let any dust, foreign materials or water get inside the pipes during connection.
• If bending the pipes, allow as large a bending radius as possible. Do not flex the pipes any more than necessary.
• If joining pipe ends, do so before tightening the flare nut.
• Always blow the pipe end with nitrogen while joining pipe ends.
(This will prevent any oxide scaling from occurring inside the pipe.)
• If using long pipe lengths with several joined pipe ends, insert strainers inside the pipes.(Strainers are not supplied.)
• When tightening the flare nuts, coat the flares (both inside surfaces) with a small amount of refrigerator oil, and screw in
about 3-4 turns at first by hand.
• Refer to the following table for the tightening torques. Be sure to use two spanners to tighten.
(If the nuts are overtightened, it may cause the flares to break or leak.)
ø6.35mm
ø9.52mm
ø12.7mm
4. After piping connection has been completed, make sure that the joint areas of the indoor and outdoor units are free from gas
leakage by the use of nitrogen, etc.
5. Air purge within connection piping shall be carried out by evacuation.

10.1.8. Heat Insulation

Use a material with good heat-resistant
properties as the heat insulation for the pipes.
Be sure to insulate both the gas-side and
liquid-side pipes. If the pipes are not
adequately insulated, condensation or water
leakages may occur.
Charging With Refrigerant
• At the time of shipment from the factory, this unit is charged with enough refrigerant for an equivalent pipe length of 30m. If the
equivalent pipe length used will be 20m or less, no additional charging will be necessary.
- For standard type
Equivalent length
30m
Flare nut fastening torque N•m {kgf•cm}
18 (180)
42 (430)
55 (560)
Minimum length
7.5m
38
ø15.88mm
ø19.05mm
Liquid-side pipes
Gas-side pipes
65 (660)
100 (1020)
Material that can
withstand 120°C or
higher