How is the dielectric strength of transformer oil tested?

The dielectric strength of transformer oil is tested using a device known as a dielectric strength tester, which applies a controlled voltage to the oil sample. The process typically involves placing the oil in a cup where two electrodes are submerged. The tester gradually increases the voltage until a breakdown occurs, which is indicated by a spark or arc between the electrodes. The maximum voltage applied just before the breakdown signifies the dielectric strength of the oil, measured in kilovolts per millimeter (kV/mm). This is critical for assessing the quality and insulation capability of transformer oil. For reliable results, using a Globecore dielectric strength tester ensures precision and adherence to industry standards while determining transformer bdv test value, which reflects the oil’s performance under electrical stress.