Here is the inside of my Westinghouse NEMA from Jace. You see a wirenut... the wire was Cut O_O. So I stripped them and then connected them together with a wirenut and it works great!
I use the screw that holds the ballast kit as grounding....but for me personally...I don't worry as much about grounding regular HX MV ballasts...unless I install them outside, then they SHOULD be grounded....but it really depends...depending on how high they are mounted....if on wooden poles, they don't HAVE to be grounded.....but if they are on metal poles, or mounted on houses or on decks or anything lower than a regular streetlight pole, it's a GOOD idea to ground it! When this fixture was still in service, this fixture was NOT bonded with grounding!
I grounded this fixture. It's hung outside at the moment. This pic was taken the day I received it in the mail I think. I grounded it in my own way though.
That's what I said Jace, all pole (except wooden and fibreglass ones) need to be gounded, however if the pole is grounded then the fixtures (connected to the pole by a metal arm) are already grounded.