I am replacing a ceiling light fixture. I have a black, white and ground wire in the ceiling box. The two wires on the fixture are the same color. How do I determine which one is "hot"? If I erroneously connect the hot wire from the ceiling box to the neutral wire from the fixture, will I damage the fixture?
2007-02-22 08:31:26 · 14 answers · asked by dan g 1 in Home & Garden ➔ Do It Yourself (DIY)
Use a voltmeter or even one of those led testers that have two probes and check the voltage between each wire and ground. The one with the voltage or that lights the bulb is hot. The other is neutral. There should be a bare wire that is ground. Be careful not to get them reversed. In a light socket the screw part is neutral and the center contact is hot. This is to protect you from touching the hot by mistake.
2007-02-22 08:36:37 · answer #1 · answered by Barkley Hound 7 · 0⤊ 2⤋
The two black wires from the fixture are the problem. One will go to the centre contact of the socket and the other will go to the threaded metal shell. Both are insulated so it really makes no difference which one you hook up. Technically, the fixture wire connected to the centre contact should be the one that you hook to the black supply wire and the fixture line connected to the threaded shell should be connected to the neutral or white supply wire. Since it is usual to have some of the threads bulb exposed then the exposed threads would be at neutral or zero voltage when the light was on. If you want to be sure then use an ohm meter to figure out which is which.
2007-02-22 09:57:29 · answer #2 · answered by frozen 5 · 0⤊ 0⤋
In the AC fixture it is important to connect a ground wire to ground. After that it does not matter at all that which of the two wires connected to fixture is hot or neutral. So just connect the two wires of the fixture to white and black wires of the ceiling box. It will will not effect at all. It will not damage the fixture.
2007-02-22 08:57:12 · answer #3 · answered by Pramod 3 · 1⤊ 0⤋
If I was installing an incandescent fixture, I'd use an ohmmeter to figure out which black wire of the fixture went to the center portion of the lamp base. The white wire would connect to the one that forms the screw that holds the bulb. (But it will work anyway.) But most prefer this so that if someone changes the bulb while the switch is on and shoves their hand all the way down so it touches the bulb base, they won't be shocked. Most people only hold the bulb by the glass globe anyway.
If the fixture is fluorescent or some other transformer using technology, won't matter which order.
2007-02-22 09:35:56 · answer #4 · answered by KirksWorld 5 · 0⤊ 0⤋
I'm beating the dead horse, but let me add a bit of triva for you. The black and white conductors in your fixture box are both "hot", in the respect that they are both "conductors". One just happens to be grounded, and is caled the "neutrl" or "grounded conductor", which mean the same. The other one (black) is the "ungrounded conductor". The notion that the neutral wire carries no current is false. It carries the same amount of current as the black wire!
As for hooking it up, if both fixture wires are the same color, it tells you that the fixture is "double insulated" so no parts of it's body except the socket contacts are able to conduct any current. That's why it has no ground wire. Hook the wires up either way.
2007-02-22 10:21:51 · answer #5 · answered by Hank 3 · 2⤊ 0⤋
It really doesn't matter, because AC is different than DC in that it's not directional, and it runs across the fixture. So just wire one to black, and the other to white. It'll be fine. It's more of an issue in the house with how it handles the ground, not the fixture itself.
2007-02-22 08:39:58 · answer #6 · answered by T J 6 · 0⤊ 0⤋
It does not make a difference it will not hurt the light but if you want to find out buy a cheap 5 dollar voltage tester at home depot and put one lead on the bare ground wire and one end on one of the wires and the hot one will light it up
2007-02-22 09:21:05 · answer #7 · answered by brndnh721 3 · 0⤊ 0⤋
Houses use AC current meaning that you can hook it up backward and the light will still come on.
Just like when you plug a lamp in, you can flip the plug over and plug it in and it still works.
The ground should be hooked to the metal case of the fixture, if it has one.
Madsci30
http://www.officialperformanceautostore.com
2007-02-22 08:37:37 · answer #8 · answered by Madsci30 1 · 0⤊ 0⤋
if you feel the wire from your fixture with your hand you will probably feel some ridges on the wire. that is concidered the neutral.
2007-02-22 10:15:13 · answer #9 · answered by sammyjk1 3 · 1⤊ 0⤋
How many switches control the fixture? You will need a voltmeter.
2007-02-22 08:34:38 · answer #10 · answered by Thomas K 6 · 0⤊ 0⤋