Measuring the Breakdown Voltage (BDV), or in other words, the dielectric strength of insulation oil is crucial in ensuring that equipment remains fully operational. It needs periodic testing to ensure that equipments can function properly over time.
An oil sample should be taken out of the equipment and should be carefully tested to check for any potential future problems. Such type of tests will usually happens either in lab or on-site, provided a portable test set equipment is available.
The higher the dielectric strength, the better, as it means the transformer will have greater electrical resistance to make sure it doesn’t malfunction easily.
The dielectric strength is primarily determined by the presence of contaminants like water and acids. As a result, it is vital to make sure the transformer oil does not comprise any such contaminants.