XO terminal transformer?

[Znogard]

What's the correct term for the XO terminal in a transformer? I have always called it "X of O".
I wonder if others have heard it refered to as "X of O"?

 

[jim dungar]

It is simply the letter X and the number 0.

It is most commonly spoken as: 'ex oh', although 'ex zero' would be more appropriate (in the same manner as other terminals X1, X2, X3, or the line voltages L1, L2, and L3).

 

[iwire]

What's the correct term for the XO terminal in a transformer? I have always called it "X of O".
I wonder if others have heard it refered to as "X of O"?

I always say XO like it is two letters. However considering the other terminals are X1, X2, and X3 I imagine it is really X0 (Xzero).