There are certain tests to test potential transformers like, Visual inspection, Voltage ratio test, Polarity test, and Burden test. Among all these Burden test is necessary to perform as it involves connecting a load to the PT’s secondary side and measuring the voltage and current.

The Potential transformer working is based on Faraday's law of electromagnetic induction. A magnetic field is produced around the primary winding when a high voltage is applied to it. The secondary winding's voltage is induced by this magnetic field. By stepping down the high voltage to a low voltage proportional to the turns ratio, the voltage is obtained.

The burden of a potential transformer (PT) is the amount of load that can be safely connected to the PT's secondary winding without exceeding its rated voltage or current. The burden of a PT is typically expressed in volt-amperes (VA) or kilovolt-amperes (kVA) and is calculated using the following formula: \(Burden (VA)=\frac{(Secondary\ Voltage)^2}{Load\ Impedance}\)

Some of the key characteristics of a potential transformer include 1. High voltage rating 2.Low voltage output 3.High accuracy 4. High insulation level: 5. Low impedance: 6. Steady-state performance 7. Frequency response

The main disadvantage of a potential transformer is that it can only step down high voltages to lower levels, and cannot be used to step up low voltages to higher levels.