A 400amp main disconnect will need to be added outside a Building. Existing is a 400 amp main circuit breaker panel in the utility room. The Arc flash rating turned out to be a Cat. 4 for the Panel.(you have to wear a space suit) so by installing a Disconnect between the Panel and the transformer, the engineer says it will go to a category 2. This is fed from a pad mount transformer with the metering mounted on the outside. Can the feeders from the transformer be spliced in the disconnect if not long enough, to go to the line side of the switch? Or will we have to install a 2'x2' junction box. Existing, is the 4" LB going to the back of the Main Panel. Sorry about the long story - Thanks, SJT