The Class of accuracy for metering CTs are 0.1, 0.2, 0.5, 0.5s and 1.0 and in case of protection of CTs, it is 5P10, 5P20 and 10P10. Other than class of accuracy, other factors need to be considered for a CT are ratio, rates burden, accuracy limit factor and knee point voltage etc.                

The Class of accuracy for metering CTs are 0.1, 0.2, 0.5, 0.5s and 1.0 and in case of protection of CTs, it is 5P10, 5P20 and 10P10. Other than class of accuracy, other factors need to be considered for a CT are ratio, rates burden, accuracy limit factor and knee point voltage etc.