"Normal" for a 75Kva, 480 delta primary, 120/208 Y secondary is 100 amp, 3 pole, primary OCP, and secondary conductors treated as a tap; termination at a 200 amp, 3 pole OCP.
3/0 Cu minimum conductors on secondary w/200 amp OCP.
BTW,some plans come in with 4/0 Cu THHN/THWN-2 spec for secondary, 200 amp OCP in 42 circuit panel. Primary w/#1 Cu, 100 amp, fused, 600 volt primary disco adjacent to xfr.
EDit.....ALL of the above are conduit/raceways.
Last edited by HotLine1; 06/20/12 10:31 PM.
