CT star point

[india68]

What Happen if the CT's Star point flipped around?.I mean If i make star point at P1 instead of P2 What difference it makes?

 

[JJHorak]

All your currents will be off by 180degrees, unless there is some other question or point you are asking.

 

[davidbeach]

Or, it may mean that the currents will be right rather than off by 180°. Don't get hung up on CT polarities; what is important is the relationship between which end of the CT is grounded and how the relay is connected. You should be having the wye point toward the protected zone; sometimes that means grounding the polarity of the CT secondary and sometimes that means grounding the non-polarity of the CT secondary, but always the end toward the protected zone.

 

[JJHorak]

You are right David. I can't say the wiring reversal will cause a 180deg shift unless I also looked at how the relay or meter was wired.