C200 means, it holds 10% accuracy upto 20x secondary rated current.
If my fault level at this bus is 20kA, 20kA translates to 166A on the secondary, which is >20x secondary rated current.
Is this a clear-cut case that I need to increase the CT ratio, to a 1000:5A CT?
Am I right that it doesn't matter anymore that the total burden is 1.008Ohms, so the secondary voltage is 168V, still less than 200V, correct? This doesn't mean anything anymore since the accuracy of the CT is compromised?