Hello, I am hoping to get some engineering calculations/general input on a step up X-former installation, my background is by and large with electronics and control systems but occasionally my job requires installation support for new machines. My Q: I need to specify the correct fuse's for 25' run (max) from the 250 amp service buss/100 amp Buss plug and cable feed down to a 208 3 phase 15KW delta transformer primary. On the secondary/load side the machine spec calls for 63 amp fuses and 16mm sq cable with the total power spec. at 23KW. An apparently identical machine model is fused at 100 amps on the buss plug to an identical 15KW transformer primary with 4/4 AWG SOOW and then looks like 6 or 8 AWG SOOW on the secondary feed to that existing older model machine. My calculations for fuse and cable size are somewhat different based on my math, I hope someone here can render the correct answers based on the info. provided. Thanks for your help.