Ummm....
How do you get 200 amps?
You will NOT pull 20 to 30 amps 'starting' an incandescent light.
White wire is neutral.
Black is hot.
Green is ground.
In the US.
250v residential lighting is not common in the US.
If the existing wiring is going through a metal box, then check for worn or cut insulation where it enters the box.
Call an electrician!
