2 black wires but no white wire (photocell-controlled fixture)


I have a condo porch light that's controlled by a master photocell on the outside wall which also turns on other exterior lights at night. You can turn the porch light on/off from inside the condo as well.
This porch light was removed/replaced years ago and now needs to be reinstalled. The bulb type is a 2-Pin G23 fluorescent.
Confusion arises because the light's housing has two black wires but NO white wire. It also has a green ground wire that appears to have not been used in the original installation (end is still insulated).
The wall box has the typical one black and one white wire, with ground apparently optional.
Can I hook one black to black and the other black to white? Or should I tie both blacks to black and cap off the white box wire? Thanks for any concepts.
J.R.
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If you are sure that there are only the two black wires on the fixture, plus ground, then connect either one to the black wire in the box, and the other to the white, connect grounds together
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Seems logical, but there's no evidence ground was originally used; an oversight on the installer's part maybe.
J.R.
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No time like the present, to do the right thing.

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So, this looks like a case where black vs. white is arbitrary? Common practice with fluorescent bulbs?
I'm trying to figure out the general wiring concept. The condo was built around 1970.
J.R.
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I would think it has more to do with the fixture than the condo. It's possible that the fixture works on multiple voltages, which may explain not having a white wire. It may also be from a foreign country
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Addendum:
I realize that tying both blacks to black would not logically allow current flow unless part of the fixture is tied to neutral, which I see no evidence of. Just taking a wild guess with that.
I've read that some black wires have a faint white stripe and are actually neutral, but I don't see such a stripe. They are also identical in surface texture.
J.R.
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J.R. wrote:

If the lamp fixture has two black lines and no white, then it probably doesn't matter which line is tied to the condo's black and white lines. If it really bothers you, you can go to the manufacturer's website and see if there is a set of downloadable installation instructions. But connect the lamp's ground to the condo's ground (and the box too if it's metallic).
--
Douglas Cummins
Calcoast - ITL
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On Tuesday, September 1, 2009 at 12:49:23 PM UTC-7, J.R. wrote:

always use the black wire on the center post of the light socket. The shell of the socket to the white of the condo.
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