Alberto, I apologize for overlooking your original post.
Unfortunately, distribution-transformer fuse sizing is typically out of the scope of the E-C.net message board. I have very little experience with this, and it was with T (slow) and not K links.
There is some limited, very general manufacturer’s information on universal-link fuses for MV-distribution circuits.
www.cooperpower.com/Library/pdf/KSEC030.pdf www.cooperpower.com/Library/pdf/02022.pdf
