CT connection for T/F differential protection

[speedtronic]

Why CTs are connected in star on T/F delta connected winding side & in delta on T/F star connected winding side for T/F differential protection?

 

[Spudmiester]

Dont know, its a while since I had anything to do with big trannys. Well........ not since I was last in Blackpool anyway !

 

[SimonCTS]

Going for a stab in the dark here.......as i haven`t yet had to deal with these,

An uneducated guess would be the star first for the intial current (spike) and the delta should stop the differentials in the phases, but i am no were near shure of the sh*t i so calmly talk about

Would be interested to know other educated opinions on it