My question is, even though I know it is acceptable in an enclosure to size the conductors to the load protection (motor protectors here) isn't there a minimum ratio ( 10:1 ) of the main fuse size to the current capacity of the conductors coming off of distribution blocks? I haven't been able to find this in the code. I usually build 1 and 2 door PLC panels with servos and vfds, so I'm trying to be careful with the 8 door vfd enclosure I'm putting together. I have a main disconnect for 3 phase 460VAC with 350 Amp fuses. This feeds a distribution block where the conductors step down to #1 AWG. From there I supply each of 4 distribution blocks, 1 for each pair of doors. From there I have #10 AWG feeding groups of 5 motor protectors through bus bars. In this setup the #10s are fed directly from 350 Amp fuses. It seems a little extreme to me. There are 154 Powerflex 40 vfds, mostly 1 hp. Each Powerflex is fed from its own Motor Protector, AB 140M-C2E-B40 for the 1hp vfds.