Potential Transformer

Potential Transformer Points : Potential Transformer, Definition These transformers are extremely accurate ratio step-down transformers and are used in conjunction with standard low-range voltmeters (100-12-V) whose deflection when divided by transformation ratio gives the true voltage on the primary or high-voltage side. In general, they are of the shell type and do not differ much from the ordinary two windings transformer except that their power- rating is extremely small. Since their secondary windings are required to operate instruments or relays or pilot lights, their ratings are usually of 40 to 100 Watts. For safety, the secondary is completely insulated from the voltage primary and is, in addition, grounded for affording protection to the operator.