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The diagram below compares the hygroscopic characteristics of POE oil with mineral oil (moisture absorption in PPM at 25°C and 50%
relative humidity).
Oil Additives
Although Emerson Climate Technologies cannot comment on any specic product, from our own testing and past experience, we do not
recommend the use of any additives to reduce compressor bearing losses or for any other purpose. Furthermore, the long term chemical
stability of any additive in the presence of refrigerant, low and high temperatures, and materials commonly found in refrigeration
systems is complex and difcult to evaluate without rigorously controlled chemical laboratory testing. The use of additives without
adequate testing may result in malfunction or premature failure of components in the system and, in specic cases, in voiding the
warranty on the component.
Unbrazing System Components
Before opening up a system, it is important to remove all refrigerant from both the high and low sides of the system. If the refrigerant
charge is removed from a unit from the high side only, it is possible for the body to seal, preventing pressure equalization through the
compressor. This may leave the low side and suction line tubing pressurized. If a brazing torch is then applied to the low side while the
low side and suction line contain pressure, the pressurized refrigerant and oil mixture could ignite when it escapes and contacts the
brazing ame. To prevent this occurrence, it is important to check both the high and low sides with manifold gauges before unbrazing.
Instructions should be provided in appropriate product literature and assembly (line repair) areas. If compressor removal is required, the
compressor should be cut out of system rather than unbrazed.
If the moisture content of the oil in a refrigeration system reaches unacceptably high levels, corrosion and copper plating may occur. The
system should be evacuated down to 0.3 mbar or lower. If there is uncertainty as to the moisture content in the system, an oil sample
should be taken and tested for moisture. Sight glass/moisture indicators currently available can be used with the HFC refrigerants and
lubricants; however, the moisture indicator will just show the moisture content of the refrigerant. The actual moisture level of POE would
be higher than the sight glass indicates. This is due to the high hygroscopicity of the POE oil. To determine the actual moisture content of
the lubricant, samples have to be taken from the system and analyzed.
Figure 14: Absorption of moisture in ester oil in comparison to mineral oil in ppm by
weight at 25°C and 50% relative humidity (h=hours)
WARNING
Explosive flame! Burning! Oil-refrigerant mixtures are highly ammable. Remove all refrigerant before opening the system.
Avoid working with an unshielded ame in a refrigerant charged system.
Dismantling and Disposal
Removing oil and refrigerant:
• Do not disperse in the environment.
• Use the correct equipment and method of removal.
• Dispose of oil and refrigerant properly.
• Dispose of compressor properly.
POE
mineral oil
500
K11.0/0593
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