The 3 - 400 watt MH factory
lights I bought at the flea market did have the 220 watt
ballast connected to the top of the light but being a jack-off of all trades I dismantled them and ran a long cord from the light to the ballast so I could remotely place the hot ballast outside the room, eliminating the excess heat. I once read a book about electricity. You must have read the same book.
Ron