Daikin FCA71AV16, Installation Manual

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• Before brazing refrigerant piping, have nitrogen flow through the refrigerant piping and substitute air with
nitrogen (NOTE 1) (Refer to Fig. 17). Then, carry out brazing (NOTE 2).
After all the brazing works are finished, carry out flare connection with the indoor unit. (Refer to Fig. 16)
NOT -;9 E
Pressure reducing valve
Taping
Brazing place
Refrigerant piping Stop valve
Nitrogen
Fig. 17
1. The proper pressure for having nitrogen flow through the piping is approximately 0.02 MPa, a pressure
that makes one feel like breeze and can be obtained through a pressure reducing valve.
2. Do not use flux when brazing refrigerant piping.
Use phosphor copper brazing filler metal (BCuP-2: JISZ3264/B-Cu93P-710/795: ISO 3677) that does
not require flux.
(If chlorinated flux is used, the piping will be corroded and, in addition if fluorine is contained, the
refrigerant oil will be deteriorated and the refrigerant circuit will be affected badly.)
3. When carrying out leakage test of refrigerant piping and the indoor unit after the installation of indoor unit
is finished, confirm the connecting outdoor unit installation manual for test pressure.
Refer to also the outdoor unit installation manual or technical document for refrigerant piping.
4. In case of refrigerant shortage due to forgetting additional refrigerant charge etc., it will result in
malfunction such as does not cool or does not heat.
Refer to the outdoor unit installation manual or technical document for refrigerant piping.
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CAUTION-----------------------­
Do not use antioxidant when brazing piping.
It may result in malfunction of components and clogging of piping due to residue.
7. DRAIN PIPING WORK
(1) Rig drain piping
• As for drain work, perform piping in such a manner that water can be drained properly.
• Employ a pipe with either the same diameter or with the diameter larger (excluding the raising section) than
that of the connecting pipe (PVC pipe, nominal diameter 25 mm, outside diameter 32 mm).
• Keep the drain pipe short and sloping downwards at a gradient of at least 1/100 to prevent air pockets from
forming.
• If the drain pipe cannot be sufficiently set on a slope, execute the drain raising piping.
• To keep the drain pipe from sagging, space hanging wires every 1 to 1.5 m.
GOOD
0
WRONGX
Fig.18-1 Fig. 18-2
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CAUTION-----------------------­
Water accumulating in the drainage piping can cause the drain to clog.
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