If the load is 50%, you should use 1HP for the calculations instead of 2.
So, at half load, the current drawn should be ~1.5A
Try to be perfect. You'll never make it, but you will be very, very good.
I believe that the closer approach to answer the question comes from “dpc” in his 16 Mar 12 10:51 post.
The equation that explains the principles of a CT is the Ampere’s law (generalized by Maxwell). It states the mutual association between the current that cross a surface and the magnetic...