Replaced a wall light with a brand new 400w metal halide wall pack on an old hotel for a customer.

Upon energizing to test it, the lamp would not light. While trouble shooting, it turns out that when only the ground wire was disconnected, the lamp would light. Of course, when the ground was connected, the bulb would go out.

Any ideas?

Bad ballast? seems like the only thing in there that would be grounded

What voltage this luminaire is wired up for ? I have a hunch it may have wrong ballast to use in there.

Merci.

Marc

It's a tri-tap ballast. The proper 120V lead is connected, the other two leads are factory sealed and unexposed.

The fixture is brand new, complete with lamp and ballast. I have used many of this same type of fixture without any problem.

I take it nobody else has encountered this type of problem before.

Is the capacitor in the fixture metallic by chance?? I would start looking at something between the ballast output lead (if not the ballast itself) and the socket accidentally touching ground or faulted to ground, and my first bet would be a capacitor with a metallic case and an internal problem ..


A.D