Art. 300.20 (B)

[jbolen]

If i have 4160 in shielded cable installed in separate connectors in top of the switch gear are the slots required to be cut into top between the penetrations to reduce inductive reaction.

 

[don_resqcapt19]

Assuming that the enclosure is ferrous, the code requires slots. Also the connectors and locknuts need to be non-ferrous. That is the code answer, but unless the current on each conductor exceeds 200 - 300 amps, it is unlikely to be a real world issue. If you don't want to cut slots, you can cut an opening in the top, and install a non-ferrous plate that all of the connectors enter.