12000A Utility Connected to 6000A Bus

[kingpb]

I'm failing to understand how you can legitimately connect up to 12000A utility source to a bus rated 6000A, assuming tie breakers are closed. The total load on the 6000A rated bus is maximum 5413A but seems wrong to have all 4 utility mains closed. What am I missing?

 

[ron]

Think of how the load will be drawn from those 6000A bus', and the path of power.

The load flow and Kirchhoff’s Current Law is likely how it can be 6000A.