Power Distribution Tap Box/Connection

Designing a power distribution system for a series of transportable containers where one container houses the transfer switch and UPS system. Feeding out from this container to other containers.

Being transportable (one time), the preference is to be able to take down from a staging/testing area and transport to another location where containers will be arranged (further apart) whereby conduits will be run and the power connections re-established at the power feed container.

The design approach is to integrate a tap box on the exterior wall whereby I can easily connect the sub feeds to there respective containers to some typical bare wire terminal lugs.

In the past, the approach has been to fashion either a custom fab box or commercial weather-grade enclosure with huge terminal blocks (in/out) where the inside power is routed from a panel inside via wireway to this box and attached to the large terminal blocks. I venture to say that this approach steps into the bounds of arc flash and/or fault current spacing concerns.

In other cases, the approach has gone to the expense of adding another disconnect (breaker) as the tap point; an expensive and unnecessary (disconnect or trip).

Is there a product that facilitates a conductor connection (i.e. bring conduit to this box, break out conductors and make connections) that already conforms to power distribution guidelines (400A, 100A, 415VAC, etc) other than using a connector.