I am working on an TI  at a strip mall and the store is fed from a 200 amp CB from lower level switch gear to a transformer disco in store.  Transformer is a 3 wire 480 to 120/208  Delta Y  that feeds a 400 amp panel. The load is 103A   And the feeders are 2/0 cu    Even though this is existing, the  inspector will not sign off the TI work we did unless we either replace the 2/0 with 3/0 or install a 175A  CB  Is there something we are missing code wise that allowed this installation in the first place. It was obviously engineered inspected and approved when the strip mall was built.  Any input is appreciated
	
		
			
		
		
	
				
			
				