Oil Additives - Emerson Copeland YB56K1G Application Manuallines

installed in all PAG systems. This will maintain the moisture level in the oil to less than 50 ppm. If
PAG oil is charged into a system, it is recommended that its moisture content be no higher than
50 ppm.
PAG
Figure 22: Absorption of moisture in POE/PAG oil vs mineral oil in ppm by weight at 25 °C and 50 % relative humidity
(h= hours)
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 3 mbar or lower. If there is
uncertainty as to the moisture content in the system, an oil sample should be taken and tested. Sight
glass/moisture indicators currently available can be used with R290 refrigerant and lubricants.
However, the moisture indicator will only show the moisture content of the refrigerant. The actual
moisture level in the oil is likely to be higher than indicated by the sight glass. This is due to the high
hygroscopicity of PAG oil. To determine the actual moisture content of the lubricant, samples have
to be taken from the system and analysed.
6.7

Oil additives

Although Copeland cannot comment on any specific 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 difficult 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 specific cases, in voiding the warranty on the component.
32 AGL_Ref_ST_YBK1G_EN_Rev01