What is the Maximum No Load Current % in Transformers?

Try reading about this here

I'm not sure there are standards for this. I believe that you will find that a large part of the variation has more to do with the construction of the magnetic core. One of the reasons that magnetic cores are made from layers of metal is to reduce the amount of eddy currents circulating within it. In order to get a standard, all cores would have to be very nearly the same. That is a little bit like saying that all cars must be the same.

Thanx a lot ..