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it is a transfoermer of 1500 kva, 3 ph, 13200 volts primary, 480/277 volts secondary, %z=5.75, i calculated the size of fuse as follow:
nominal current on primary side= 65.6 A
size of fuse= 65.6 x 2.4 = 157.45 A
i select a 150 amperes fuse
am i right or wrong?
if i am wrong can somebody help me, how can i calculate a k fuse?.

thanks anyway

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