Question about flourescent lights?

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bbe

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Changed out a fixture for a customer, changed to a flourescent fixture the home didnt have a ground wire. Checked voltage before putting bulbs in was surprised to see voltage from the fixture to neutral . Hot to neutral was correct , neutral to fixture was about same, removed the ground wire from ballast to fixture the voltage went away. the voltage was coming from the ballast on its ground wire. Can anyone please expalin this to me?
 
bbe said:
Changed out a fixture for a customer, changed to a fluorescent fixture the home didnt have a ground wire.

Then you have a choice, use a non metallic fixture or run a grounding conductor or provide GFCI protection. See 410.42 and it's exceptions.
 
MD I checked it with my fluke meter but now that you said it maybe could have been ghost voltage , didnt think to get the wiggy... But is there any reason there would be voltage on the electronic ballast ground wire.
 
bbe said:
But is there any reason there would be voltage on the electronic ballast ground wire.
Not that I can think of, but seldom do I see a ballast with a ground wire. As Bob rightly points out, there isn't really any relief in teh code that would even permit you to install this fixture on an ungrounded circuit in the first place. I do understand that it probably happens 1,000's of times a day.
 
mdshunk said:
Not that I can think of, but seldom do I see a ballast with a ground wire. As Bob rightly points out, there isn't really any relief in teh code that would even permit you to install this fixture on an ungrounded circuit in the first place. I do understand that it probably happens 1,000's of times a day.

Ballasts are grounded when they are physically screwed to the metal frame of the fixture.
 
mdshunk said:
Not that I can think of, but seldom do I see a ballast with a ground wire. As Bob rightly points out, there isn't really any relief in teh code that would even permit you to install this fixture on an ungrounded circuit in the first place. I do understand that it probably happens 1,000's of times a day.

Ballasts are grounded when they are physically screwed to the metal frame of the fixture.
 
480sparky said:
Ballasts are grounded when they are physically screwed to the metal frame of the fixture.
No kidding? :grin:

We're talking about an actual wire, which you see sometimes. I can't think of any particular brands off the top of my head, but you see them sometimes. I know I've installed fixtures with factory-installed ballasts that have featured such a wire. They often have a ring terminal on them and are captured under the ballst, on the stud that holds the ballast in.
 
physically screwed to the metal frame

physically screwed to the metal frame

I scrape the ballast/fixture paint first, otherwise starting problems.
 
480sparky said:
Ballasts are grounded when they are physically screwed to the metal frame of the fixture.
Actually, the ballast is bonded to the fixture when mounted. Grounding requires an EGC.
 
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