Grounding Halide ballasts?

[becact]

My ballasts have two wires for the lamp, a black, white and green for the power cord, and a grounding lug on the chassis of the ballast. Do I really need to ground the chassis as well (or will the ground in the power cord be enough), and if so, what the heck do I ground it to? Help!

 

[tkeracer619]

The ground tends to go to the reflectors to prevent as much stray voltage as possible.

 

[becact]

So this should be the final wiring layout? Is the green wire coming from the ballast connected internally to the ground lug on the case? Or should I cut my green to green connection and connect them both at the case ground lug, along with the reflector ground?

 

[tkeracer619]

I am pretty sure they are connected internally. Throw a meter on it and make sure.