Did I wire my light fixture correctly?

Question

I'm replacing a light fixture in an old apartment where the ceiling wiring has two brown/red wires and one black wire. When I removed the old fixture it was wired with black to black, the white wire was extended with another white wire with a wire nut and then connected to the two brown/red wires. The old fixture did not have a grounding wire. One of the brown/red wires seemed to be coming down directly from a small hole in the ceiling and the other brown/red wire was coming out from the side of the ceiling along with the black wire.

So, I took my new fixture and connected the black to black, the white to the brown/red that was next to the black and seemed to coming out of the side of the ceiling/junction box (terminology?) and then I connected my green grounding wire to the other brown/red wire that was coming down directly out of the small hole in the ceiling.

I would like to know did I wire this new fixture correctly? It seems to be working just fine and I even tested it with a voltage meter after I turned the power back on in case I didn't ground it correctly.

Answer 1

It sounds wrong to me, but I couldn't be sure without actually being there. You should connect the new fixture, in exactly the same way the original fixture was connected.

If there wasn't a grounding conductor in the original circuit, replacing the fixture did not make one magically appear. If a grounding conductor is required, you'll have to install one in accordance with local codes.

Answer 2

The wires in my house are exactly the same. Everything is run with old cotton braided wires inside a metal BX shielding. The reddish-brownish wire is neutral; the black wire is hot.

So no, you did not hook this up correctly. You should keep it hooked up the way it was before, with the white lamp-wire spliced to the two red/brown wall-wires, and the black lamp-wire spliced to the black wall-wire.

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The grounding was provided by the metal BX jacket (which is electrically-connected to the lamp via the metal box). This is not allowed by the NEC anymore, and for good reason: BX cable has high impedance, meaning it does not provide a good electrical connection to ground.

Running a ground wire through the BX cable is extremely difficult (I've tried it). Thus, I'd recommend you install a GFCI at the start of the circuit and connect everything else (including the lamp) to the 'load' side. This is required for 3-prong outlets, and though I don't have the NEC to verify, I would assume the same is true for other fixtures.