I thought I could easily replace a light fixture, but when I pulled down the old one (the house is only 7 years old) I didn't pay attention to what wires were put together... The new fixture has only three wires...the copper grounding one, and the two meant for the white and the black...but what is the red for? and why is there so many of each? There are two light switches connected to this ceiling light and one is a dimmer...is that why there are so many wires? Are both the reds supposed to be with the white wires? See the picture attached... Any suggestions? THANKS!
Put the wire nut back on the two black wires that are twisted together in your photo. Put the wire nut back on the red and white wires that are twisted together in your photo.
Connect your new light fixture between the red and white wires that are close together, but not touching, in your photo.
I think the white wire on the far left is your ground wire cuz it looks like it's connected to a screw in your electrical box. Maybe check for voltage between it and your electrical box, and for continuity between it and your electrical box. You should find no voltage in that wire, and continuity between the end of the wire and the electrical box.
There should be a place to connect that ground wire on your new light fixture.
Your two switches are three way switches that allow either switch to turn the light fixture on or off. Your wiring is exactly the same as the wiring in the following diagram which shows two three way switches controlling a single light.
All you have to do is imagine that the black insulation on the black wires in that diagram is red, and the red insulation on the red wires in that diagram is black. Then, your photo and the diagram will be identical.
You don't need to read the rest...
... but I have a cute little puppy here, and if I find out that you didn't read the rest of this post, I'm going to put him in a sack with a concrete block and throw that sack in the river.
Electrical power comes into your house on a cable with three wires in it; a black wire, a red wire and a white "neutral" wire. Both the red wire and the black wire carry 120 volts AC, but they're out of phase by 180 degrees, so that when the black wire is at +120 volts the red wire will be at -120 volts and vice versa.
So, you'd measure 120 volts between the black and white wires coming into your house, 120 volts between the red and white wires coming into your house, and 240 volts between the red and black wires coming into your house.
The technically incorrect but easiest way to understand house wiring is that the power comes from the generating station on the black and red wires, and goes back to the generating station on the white wire.
Now, you'll notice that you also have two rows of connections in your house's electrical panel. It's easy to make the mistake of assuming that all the wires on one side of the panel are connected to the red voltage source and all the wires on the other side are connected to the black voltage source.
That's not true. It's the buss bars inside the panel that determine what gets connected to what.
So, even though the red and black wires COMING INTO your house both carry 120 volts AC and are 180 degrees out of phase, you CANNOT assume that the black and red wires going to electrical outlets, light fixtures and ceiling fans inside your house are the same. When the electrician is wiring your panel he doesn't know which breakers are connected to the red voltage source and which are connected to the black voltage source, and he'll connect red and black wires to ANY available slot in your panel.
So a red wire could be connected to either the red or black voltage source and ditto for a black wire. Don't be surprised if you measure either 0 or 240 volts across two black wires in your panel, between two red wires in your panel, or between a red and black wire in your panel. The same thing goes for red and black wires in adjacent electrical boxes.
So, some of the lights, electrical outlets and ceiling fans draw their power from the black cable coming into your house, and some draw their power from the red cable coming into your house, and whether the wiring going to those lights, fans and electrical lighting is red or black is anyone's guess.
Now, you'll also notice that some of the electrical appliances in your house operate on 240 volts AC, like your electric stove, clothes dryer and central air conditioner. In those cases there will be three wires from the electrical panel going to the 240 volt appliance; a red wire carrying 120 volts, a black wire carrying 120 volts (and 240 volts between them) and the white wire that carries the electricity back to the generating station.
THAT MEANS that every 240 appliance in your house will have TWO breakers; one for the red wire and one for the black wire, not just one.
So, if you ever do any repairs on the 240 volt appliances in your house, remember that you have to trip BOTH breakers to that appliance off before it's safe to stick your fingers in there.
PS: The puppy thanks you.This message has been edited. Last edited by: Nestor,
Nestor, I'm gonna sic the ASPCA on you :-D
seriously... here's another case where somebody in a hurry and without training didn't "recode" a white wire when it is being used for something else.
don't be that fool in the future.
at least one of the "white" wires is actually a hot wire going to the back side of a switch. it is worth making sure the power is off at the circuit, then taking the switch assembly out of the box... checking with a non-contact "chirper" to be sure the lines are dead before touching... and matching them up with the stuff in the ceiling. an ohmmeter or test light will work.
at that point, use of some differently colored 3M 35-series coding tape to identify the wires forever is advised. "recode" means take a wacko color, like say blue for this one and purple for that one, and wrap both ends to make them "different" from everything else.
at that point, you can easily diagram what you have. wires left over are probably going to be white, black (or red), and ground supply, and you know what they're good for.
I rather suspect they ran a 3-14/WG down to the switches, with power on one wire, dimmer return on one wire, and on/off return for the fan alone on the last wire. and once you know that, the rest should be easy.
(for reference, if I'm right, black is one switch or dimmer, red the other, red/white pair is feed to the switches, white and ground separates as advertised. but that's pure speculation)
if not, it's electrician time.This message has been edited. Last edited by: swschrad,
sig: if this is a new economy, how come they still want my old-fashioned money?
One colored Sharpie could have saved the day here. For what it is worth using Romex whites for other purposes than the neutral is NEC legal, if you mark that white wire in any color other that gray [which I never use] or green. Methinks the wire on the left is bare copper painted while the house was sprayed, for what that is worth as well.
Plus I have found that using the white neutral [color changed of course] for the switch leg when ever possible also makes following the work easier.This message has been edited. Last edited by: CommonwealthSparky,
"Why isn't everyday Earth Day ?"
before you put the switch cover back on use a magic marker and write the circuit breaker # on the back. no more guessingThis message has been edited. Last edited by: beers1,
I knew that that white wire was being used as a traveller and should be marked, but I figured that the post was gonna be long enough if I just explained why the diagram I provided was the same as the wiring in the photo, even though the wires were different colours.
... wanted to avoid information overload.
Sparky: You said: "if you mark that white wire in any color other that gray"
What's the reason that they don't want you to mark it in gray? What's the issue with gray?This message has been edited. Last edited by: Nestor,
I'll answer that one:
While the most common color for the neutral wire is white, electrical code also designates gray as a neutral wire.
Just like the hot wire can be black, red or blue.
Ground wires are green or green with a yellow stripe (and of course, bare).
That's U.S. code, not sure if this applies north of the border in Nestorland.
When working with say THHW stranded cable many a spool of gray was returned to my supplier. I'm confused enough as it is, don't need no help....
"Why isn't everyday Earth Day ?"
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