Panasonic CU-YL28HBE5 Service Manual page 50

10.2.8. Connecting The Pipes
• Use a clean pipe which does not include water or dust for inside of piping.
• When cutting the refrigerant pipes, a piping cutter must be used. Before connecting the refrigerant pipes, blow nitrogen and blow
off dust in the pipes.
(Never use tools which cause a lot of dust such as a saw and a magnet.)
• When waxing replace nitrogen inside the piping after removing dirt and dust. (In order to prevent oxidization scale from forming
inside the piping).
• The refrigerant pipes are of particular importance.
The installation work for refrigerant cycles in separate-type
air conditioners must be carried out perfectly.
• Set the lower limit of the allowable pipe length to 7.5m.
If the pipe is shorter than 7.5m, the refrigerant may become
overfilled and a problem such as abnormal high pressure
could occur.
1. Local pipes can project in any of four directions.
• Make holes in the pipe panels for the pipes to pass
through.
• Be sure to install the pipe panels to prevent rain from
getting inside the outdoor unit.
[Removing the service panel].
(1)Remove the two mounting screws.
(2)Slide the service panel downward to release the
pawls.
After this, pull the service panel toward you to remove it.
2. 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.
• Maximum allowable one-way piping length is the larger
numerical value between (Lo + La) and (Lo + Lb).
• For twin type, only the main piping can be reused among
the existing piping. Brandnew standard pipe should be
installed for branch pipe/branch piping.
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