Huayi Compressor Barcelona, S.L. Antoni Forrellad, 2 · 08192 · Sant Quirze del Vallès · BCN · Spain.
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2. Compressor mechanics are lubricated with liquid refrigerant
When injecting the entire refrigerant charge at once and high-speed, part of it vaporizes, but the majority remains in
liquid phase and places itself in the bottom part of the compressor. The oil stays above the refrigerant, in contact with
the moving parts of the compressor mechanics.
When starting up the compressor shortly after fi nishing the charging process, the crankshaft oil pump is pumping only
refrigerant from the compressor bottom part, and not oil, so that bearings are not lubricated.
Moreover, while pressure decreases, refrigerant evaporates taking oil with it and foaming. This mixture reaches the
suction inlet and gets into the refrigeration circuit. The quantity of oil in the crankcase during the fi rst minutes after
starting up may not be enough and, in any case, its lubrication effect will be poor since it is solved into the refrigerant.
This may result in sizing up or creating important damages on the bearing surfaces.
This problem happens at the beginning of operation and seizure may already be formed during the fi nal checking of
the appliance.
For that reason, apart from the above refrigerant charge guidelines, we suggest to:
– Let some time pass before starting up the compressor, once the charging is fi nished, in order to allow the refrige-
rant to vaporize completely.
NOTE:
This recommendation does not apply if refrigerant charge is made in vapor state.
Also, since there is a limitation for charging natural refrigerants (R600a, R290), the recommendations given in this note does
not apply in this specifi c case.
