Thanks for the reply.
At bontorhumala, Yes I got such result for all the current channels and as you said VRMSOS is OK below 12 bit resolution.
At dlath, My maximum current is 40A, working on 50Hz AC system. Using CT of ratio 2500:1.
My burden resister is 10ohm. Burden resistor is not center tap.
As you said the test current & min. current are very close. I will try with some greater test current & will post.
Here is my schematic.
