Knowledge is power essay

  The electrical instruments are not directly connected to the meters or control apparatus of high voltage for safety purpose. The instrument transformers like voltage transformer and current transformer are used for connecting the electrical instruments to the measuring instruments.These transformers reduce the voltage and current from high value to the low value which can be measured by conventional instruments. The construction of the current and potential transformer is similar as both have the magnetic circuit in their primary and secondary winding. But they are different in the method of working. There are several types of differences between the voltage and the current transformer. One of the major difference between them is that the current transformer converts the high value of current into low value whereas the potential or voltage transformer converts the high value of voltages into low voltage. Some other differences between the current and the potential transformer are...

BDV  is Breakdown voltage value of insulating oil of the transformer. It refers to the dielectric strength of transformer oil. Transformer oil act as an insulating medium and also as a coolant that dissipates heat of the transformer. Now after a long-term operation transformer oil loses its properties slightly and a dip in dielectric strength is observed due to impurities or moisture in the oil. We have BDV tester kits to test the  Breakdown Voltage  of the transformer oil. BDV test kit Oil collected from the main tank is filled in the chamber and is placed inside the tester kit. The two electrodes you see are seperated by 2.5mm. Now high voltage at a rate of 2KV/s is applied between the electrodes and observes the voltage applied when sparks occur between the electrodes. The test is repeated minimum three times and the values are recorded. It gives the value of voltage at which the oil loses its dielectric property. A BDV rating around 30KV is considered good. If lower v...