Notes For Work Procedures - Daikin VRV Plus Series General Information Manual

Si33-003.book Page 169 Monday, June 25, 2001 9:06 AM
SiE33-003
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Notes for Work Procedures

Brazing connections
Flaring work
Charging refrigerant
Air-tightness test
Caution For servicing the models with the new-type refrigerant, strictly follow the above instructions and
precautions. Otherwise the system may get in trouble. For details on handling the new-type refrigerant and
the related work procedures and tools, refer to the Installation/Test Run Manual published by Daikin.
New Refrigerant R-407C
Precautions in Servicing the Models with New-type Refrigerant
With the new type of refrigerant, much more care must be paid to keep impurities from coming in. In
brazing the pipes, be sure to blow the pipe using nitrogen gas.
In any other connecting works, much stricter process control is needed to prevent impurities from
coming into the pipes. For this purpose, take appropriate measures such as covering the pipes and do
the vacuum drying.
Chamfer (file) the pipe ends as specified. Be very careful not to allow cuttings to come into the pipes.
To avoid leak, apply a proper amount of refrigerant oil over the inner and outer surfaces of each flared
section. As the refrigerant oil, be sure to use synthetic oil (ether oil, ester oil, alkyl benzene oil or their
mixture).
Be sure to charge the new-type refrigerant in liquid phase via the service port of the liquid-side stop
valve (outdoor unit). At this time, give vacuum drying with a vacuum pump. Never try the air purging.
Be sure to conduct air-tightness test.
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