Refrigerant:
Refrigerant R-22, R-134a and R-404a 99.9% in purity should be used for apparatus. 99.95% is recommended, if possible. In particular, the refrigerant containing the minimum volume of chloride should be used.
Oil returns:
- It is important for the piping to be designed with sufficient consideration given to oil return during the refrigeration cycle since the refrigeration oil in the compressor is sometimes discharged in volume inside the equipment as a transitional phenomenon (due to the strong of the refrigerant) during start-up, etc.
- If the Condensing Unit is positioned above the evaporator, it is important to fit siphons along the suction line every 2m of difference in height, so as to guarantee oil return to the compressor. In any case, along horizontal stretches, it is important for the suction line piping to have a slope of at least 3% towards the compressor.’
- Oil is liable to collect when an auxiliary accumulator is attached within the refrigerating cycle, which necessitates an oil-return structure. Care is required with short ON/OFF cycles.
- It is necessary to confirm oil return with above care. Please confirm that the oil level is sufficient to the operation standard, running with the compressor equipped with sight glass, in the unit operation limit condition that high to low ambient temperature, on the mode pull-down, ON/OFF cycle.
