Originally posted by: Rozek
. . . As You say "it is usual practice to earth star point" , " however not having it done it will make no operational difference whether the secondaries are earthed or not". . .
If we are talking LV, then it doesn't really matter and in my opinion will not contribute to the safety of a CT circuit - there are far more dangerous things you can do, such as open-circuiting it!
If we are talking HV, then the earth connection is your last line of defence to a fault in the CT chamber raising the potential of the CT wiring towards the phase voltage, with all the equipment / personnel damage that is likely to cause.