When it comes to performing preventive maintenance drives for transformers, the oil is what is checked first. As that is something that allows heat transfer for the transformer but also helps in insulation. While cleaning and ensuring that the transformer is in its best condition is a must for all, the oil check is something that gives an assurance that the machine would be working fine while the other things are in place as well.
When it comes to oil testing of transformer, there are multiple oil aspects that one has to take care of. Right from checking the water content to the presence metals if any and much more, there is a lot that the experts have to take care of. Read on to know about how transformer oil is tested.
The color of the oil is tested by comparing the same with oil kept aside previously from the same machine of course. If the color has darkened, it is an indication that there is contamination taking place or there is arcing with the transformer.
Dissolved gas analysis
When it comes to the oil usage in the transformer, it is known to undergo a lot of thermal and electrical pressure, and that is often known to contaminate with gases. The oil sample is checked for the presence of dissolved gases, and that is replaced with good quality oil with no presence of any gases that would allow the transformer to perform normally.
Dissolved metals testing
When it comes to the transformer being in use, there may be chances that the oil is contaminated by metal coming from contaminants as well as things that aid in oxidation. It can also happen that the mechanical wear and tear of the transformer has led to metal contamination. By using the coupled plasma atomic emission spectrometry (ICP-AES), it is tested and accordingly is the oil changed as and when required.
Testing of moisture content
When there is moisture or water mixed with the transformer oil, it is something that can lead to flashover that can gradually make the transformer dysfunctional. Experts for transformer oil test are known to test the oil for any water content, and accordingly, there are steps taken to ensure that the oil is in usable condition.
Pour point testing
When it comes to the flow of the insulating oil, there is this temperature that is to be maintained. When the experts come over for the testing, they are known to check the temperature and accordingly rectify things. This is a test that is often seen in areas that have a colder climate compared to the rest.
The visibility of the oil
When the experts for testing of transformer oil for its various other problems, they are known to also check for its visibility. Transformer oil; is generally clear and when they come to inspect, a sharp beam or a flashlight is passed through the oil and checked for its cloudiness, presence of contaminants or any other object or particles that is ruining its quality.
While there are several other oil testing ways as polychlorinated biphenyls, neutralization (Acid) number, furanic compounds, dielectric breakdown voltage which helps in better oil testing.