Confirming ground on T9 ballast?


Old 01-05-19, 04:25 PM
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Confirming ground on T9 ballast?

I had to replace a dual T9 ballast (the FC12 circular style lights) and went from a 3 wire ballast to a 2 wire. While the light works now, I want to make sure I wired it Safely before I kill myself or someone else.

Source in ceiling had black/white/green hot/neutral/ground wires, so I used wire caps to wire hot and neutral to the ballast, then ran the green ground to the mounting bracket screwhole on the ballast case. Ballast states to ensure case is grounded.

I'm not not great with multimeters, but tried following points:

Hot wire + neutral wire = 120v
Hot wire + ballast case = 12.5v

Im worried the case is NOT properly grounded. Is this assumption correct? If I understand the basics here, I should be getting 120V on the ballast case. If so, would scraping the paint off better and ensuring contact with bare metal on the case yield a 120v reading?

For what it's worth, I still had the bulbs plugged in.

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Old 01-05-19, 04:42 PM
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Welcome to the forums.

Hot wire + neutral wire = 120v - correct.
Hot wire + ballast case = 12.5v - should also be 120v.
Neutral + ballast case should be 0v.

You don't have a full ground at that location.
Old 01-05-19, 06:02 PM
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The green source ground should also be connected to the fixture frame.
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