Looking back at your original post, you said:
"if the lamp wattage is 1000W, input current to the circuit will be 1000/230V "
This is incorrect. Nothing in the ballast or lamp operates at 1000W and 230V. You are taking a wattage from the lamp and the voltage from the input to the ballast...
The ballast probably contains a transformer. The transformer steps down the voltage to the 110V the lamp needs, and at the same time, it steps up the current.
Kirchoffs law doesn't apply because the transformer makes two separate isolated circuits, thus the current can be different.
Steve
What if one fuse blows. Then you will have only have 240 across the lights. And the second transformer will backfeed the primary and the open fuse.
Why not just get a 120 to 480v transformer, or fixtures with a 240v ballast?