CT Saturation Calculations: IEC standards and nonconventional instrument transformers

This article, completing a series of three articles, presenting themes related to current transformers (CTs), including test results, designed and tested from the viewpoint of the International Electrotechnical Commission (IEC) standards and practices outside of North America. Although Ohm's law and Maxwell's equations are the same everywhere, how CTs are specified and the responsibility of the different actors can be very different. It is important for engineers to be aware of these differences when executing applications in different parts of the world.