High voltage (4160) single conductors 750 1.43 dia. 3sets of 3 and 6 sets of 3.Only reference for Single conductors on installtion is 392(B)2 which refers you to 392.3(B)(1) . 392.12 Says they can be grouped or bundled . The way 392.12 is written it looks like even thought you bundle them. The tray must be sized as thought they were laying side by side.Am I reading this right??? I know the way there installed affects there Ampacity. Per 392.13(B)