Current Transformer

Man you got to be kidding... It troubles me to think you may not be!

Do a little research on transformers and come back later, when you have a worthwhile question or questions. You obviously have access to internet as you have posted here.

I believe nobody has got my point. What I want to know about is how to connect a measuring CT to an EHV circuit to measure its current. Lets say a 9000/5 CT has been connected to a 400 KV AC line. Can anybody give the circuit diagram of that CT connection?

The CT looks like a doughnut. The 400 KV line passes through the hole. The secondary terminals are wired to an ammeter that actually measures 5 A, but has a dial scaled to 9000 A to match the CT.

I agree with you. Some of these posters are out for foul play but lets give the benefit of doubt. Current Transformers are used for stepping down current and not voltage. Voltage transformers (VT or PT for lower KVA) are used for stepping down voltage from higher to lower value. Power Transformers are used for distribution (500 KVA and above?).

I might post a CT schematic diagram showing primary and secondary sides later when find time in hand :)

A schematic or a CAD dwg?

Are you really asking what happens in the secondary of a step-up transformer?

Really?

Basically we know that a transformer can transform only voltage. The current gets transformed because of transformation of voltage. Now in current transformer the current gets reduced in secondary side as the voltage gets stepped up. So when a CT is connected in a high voltage circuit to measure current, it will cause very high voltage to be induced in the secondary side. Noe no ammeter in the world as far as I know, can operate in that high voltage. So how this ammeter is connected in the secondary side of the CT so that it will measure the actual current without getting ruptureddue to high voltage. I need the actual circuit diagram of the CT connection appreciating this high voltage concern. Can anybody please give that?

It might have helped to read post 6 before writing post 7.

Oh. Really so?? I don't understand if post 7 bothers to read then why reply to that! It would be better if you do not waste your time in replying to this petty question of mine. There might be some guys who are at lower level than yours and they might answer my silly question. Thank you.

I can't easily do pictures with this computer, but post 6 describes the very simple schematic in very simple words. If you don't understand it, you need a new line of study and/or work. You could also Google "current transformer" and probably get lots of schematics, mostly along the same lines as each other.

Yes, really so. If you cannot grasp in words what you need to in order to stop from killing yourself on a high kV line then you are definitely out of your league. Guys at a lower level are just as likely to get themselves killed. You don't get picture books in college.

There's an old adage: RTFQ, RTFA

...nuf said.

Mr. Cuba pete or whatever you are, I don't know what you think of yourself. But one thing is clear, you donot work in a practical field, or else you could have understood what my question was. And yes, they donot supply picture books in college and for that I donot need your advice. And I have not read the picture books or else I could have not asked the question.First understand the question and then come to post. this forum is I believe to be a forum of professionals. If you do not feel good about the question then do not post to the concerned thread. There will be no problem for the thread if you do not answer. Thank you.

A current transformer is clearing as instrument transformer in which the minor current is significantly relative to the primary current. it reduce high voltage current to a much lower value and it provide a suitable way of safety monitoring the real electrical current flowing in an AC Transmission line using normal ammeter.