The effect of winding potentials on current transformer errors

The effect of winding potentials on the errors of a current transformer are discussed, and the concept of a voltage coefficient for each winding is defined. A method of measuring these voltage coefficients, based on superposition principles, is given. The influence of various design features, such as the method of changing ratio, internal shielding, and the proximity of grounded surfaces are discussed. Methods are also given for making current transformer errors essentially independent of winding potentials.