Moisture contamination, and in extreme cases water droplet formation, in transformer, hydraulic, and lubricant oils can lead to a variety of problems and impact their performance. Monitoring water activity in oil can provide valuable insights into the degree of degradation and thus prevent the formation of free water. In critical processes that rely on flawless oil performance, online monitoring of water activity is crucial. The SHT4xI-Digital sensor allows for monitoring dissolved water in oil to avoid reaching the saturation point and formation of free water, and therefore enables damage prevention, lifespan extension of machinery, and optimal performance throughout the lifecycle.
It is well known that moisture continues to be a major cause of problems in transformers and a limitation to their operation. Particularly problematic is excessive moisture in transformer systems, as it affects both solid and liquid insulation, with the water in each being interrelated. Water affects the dielectric breakdown strength of the insulation, the temperature at which water vapor bubbles are formed, and the aging rate of the insulating materials. In the extreme case, transformers can fail because of excessive water in the insulation. The dielectric breakdown strength of the paper insulation decreases substantially when its water content rises above two to three percent by weight. Similarly, the dielectric breakdown voltage of the oil is also affected by the water activity (aW) of water in oil. The maximum loading that is possible while retaining reliable operation (i.e., preventing the formation of water vapor bubbles) is a function of the insulation water content (ppm).
