It is done per the applicable specification to which it has been built.

Give us some USEFUL information, maybe you will get some free advice.

Please tell us you are a student and not an "engineer".

lyn--

This is knowledge sharing site.

Not EGO hurting site, it seems you have lack of knowledge or ignorance to CT subject, but trying to reply at each form.

May be you just select your topic of interest and reply at forum instead of asking or giving advice!!!

Connect a zero deflection galvanometer to the CT secondary terminals such that the galvanometer positive is connected to terminal S1 of the CT and the galvanometer negative is connected to the terminal S2 of the CT. Now, connect a 9V battery through a push switch such that the battery positive is connected to terminal P1 of the CT and the battery negative to the terminal P2 of the CT. Now, when the push switch is pressed ON, the zero deflection galvanometer would deflect in the positive direction, if the assumed P1, P2, S1 & S2 are correct. If the galvanometer deflects in the negative direction, then either interchange P1 & P2 OR S1 & S2. (Do not interchange both).