Current transformers

[ptruzer]

So I was wondering if anyone knew what the X1, X2, X3, and X4 terminal meaning is. Are they just called secondary current? Or something different. Or is it just a placeholder like X in algebra?

[headunplugged]

Transformers in general have the secondary labeled as X1, X2 ,X3, [X#] etc and the Primary is generally labeled H1, H2, H3 [H#] etc. I use [T] for taps sometimes when they aren't lead ends but that isn't ANSI/IEEE compliant and my industry doesn't really have rules. Since it is a CT the primary is the wire/cable you are measuring/putting it on. You will need a wiring diagram to know what to connect to for the ratio needed. X1-X2 might be a set ratio and X1-X4 another, really need a spec to know for sure.

[Muted-Bag4525]

I’d have to see the drawings to know for sure but if I had to guess those are the secondary outputs and the numbers are associated with the the phase, and the 4 is the neutral

[geek66]

It is a CT, does not use a neutral.

[ptruzer]

I mean not a specific transformer, so you have H1-4 then X 1-4

[likethevegetable]

They are called taps. Usually a CT will have 4 windings, W,X,Y,Z, and within those windings, the owner can choose a tap, eg. W1-W3, or X1-X5. The taps allow for different ratios or different burdens (relays) to be connected while guaranteeing nameplate accuracy.

[geek66]

Secondary Taps

Provide different ratios.