“Water in insulating liquid may be present in several forms: dissolved water, water in suspension (emulsion), free water in the form of water droplets or water accumulated at the bottom, and water bound to polar compounds, existing due to insulating liquid aging and deterioration. According to ASTM D1533, water content of the insulating liquid is measured in ppm by weight or mg/kg. However, to estimate the effect of water on dielectric breakdown strength, the %RS value is a more adequate quantity to use. Thus, the importance of measuring water content in insulating liquid is in measuring and comparing water content with the values given in [IEEE C57.106-2015].”
(Quote from IEEE C57.106-2015)
What method is used to analyze the sample?
ASTM D1533
IEC 60814
How do you interpret the results?
IEEE C57.106-2015
What do the results indicate?
“Electrical characteristics of an insulating liquid may be affected deleteriously by excessive water content. A high water content may make a dielectric liquid unsuitable for some electrical applications due to deterioration of properties such as the dielectric breakdown voltage. These tests are suitable for use in acceptance specifications, in control of processing, and in evaluating the condition of dielectric liquids in service.” (Quote from ASTM D1533-20)