Current transformer selection

[carlosjonez]

Why do current transformers have to be made out of different material (and become huge) because of high current when the CT does not come into contact with the power at all? Is the physical size just due to the amount of windings you need to reduce the current down to something more measurable?

[Jimbo]

Transformer size is purely down to the wattage it has to handle, therefore large wattage, large transformer. Dont forget which ever way you are stepping the current will magnified as the voltage changes. Regards Jimbo