Here is the situation:

An existing 600A disconnect with parallel 350MCM per phase in 3-1/2" conduits that leaves the bottom of the disconnect and goes underground immediately. The disconnect is surrounded by other service equipment (multiple services) and there is not much room.

An ASCO automatic transfer switch was added to this feeder. The contractor mounted the switch nearby on a new concrete pad. To get from the disconnect to the ASCO switch and back the contractor installed 8" wireway and 3-1/2" conduits. That part looks fine. Inside the disconnect however you have parallel 350MCM leaving the load side of the disconnect going out the side of the disconnect through 2- 3-1/2" chases then you also have the same parallel 350MCM's coming back from the ASCO switch through 2 more 3-1/2" chases. Then splices were made to the underground feeder in the disconnect. So in the disconnect you have a big pile of splices and wire, but it is the same feeder, not a foreign one. Burndy Unitaps were used which helped on space but the disconnect is crowded.

Outage time was a concern, I think, since the service is for a call center type business.

Not sure there was another way to do it without huge expense (i.e. digging up half the parking lot and rerouting conduits).

Code violation?