Currents in shorted CTs

[dejjones]

Some colleagues, whilst doing primary injection testing,were measuring currents in unused shorted CTs. The CTs were 1200/1 with a centre tap, and all secondary terminals were shorted together. All results were as expected except in one CT they measured appreciable current in the centre tap wire, and unbalanced currents in the 2 outer wires. A discussion as to the likely cause of this raised the following question which we were unable to answer.

If we had a 1200/1 CT with an intermediate tap, but not a centre tap,(eg 1200/800/1, say)and we shorted all secondary terminals, how would the secondary currents be distributed?

Can anyone help?

 

[Alex68]

I consider the star equivalent of a three winding transformer with the secondary and tertiary windings short circuited. Then imposing the primary current, I calculate what I desire to know.