How should I connect a light fixture to this box with four cables?

Question

Can anyone tell what is going on in this box? Why are there four plain copper wires? Why is there only one red wire? What is the purpose of the brown bundle of wires that contains a black, white and copper wire? Is this even safe?

Also, is it safe to attach this very simple light fixture?

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UPDATE I have since discovered both with everyone's kind support and a pal that this is a switch! I also after finding this out, discovered there was no fuse blown, only that the switch circuit was not complete (when I separated all the wires like a dingus) and the power to the other room's outlet and lights (and light switch) were out! I have more work to do because I cannot for the life of me figure out which collection of black wires will work for the lamp to complete the second switch circuit! Picture and more details to follow!

Answer 1

This is not even close to the box from hell. Why are there 4 bare copper , your home was wired with grounded NMB type cables each cable has a ground so there are 4 how can I tell? The number of and colors of black white & red wires. All the grounding conductors or bare copper should be connected together.

Why is there only 1 red wire. This cable is quite normal in a ceiling fixture, if you pull the light switch you will probably find the other end of the cable in that box. Red and black are “hot conductors” normally 1 for a light and the other for a fan. What is the brown cable for? Without knowing how things were connected we can only guess but there are many colors of nmb cable I have seen brown in the past there is nothing special about the color in this case modern coloring identifies the wire size white is 14 awg , yellow is 12 awg and orange is 10 gauge. This is not always the case as this is a more recent change in the past they were all white for the most part. Gray usually identifies the cable as UF or underground feeder.

You ask if this is safe? Was a light hooked up previously? And how was it wired? I would say it probably was safe but now to get it back to a safe state we will need to know where the wires go to connect them up safely. The red cable that is all tied together is probably a spare we can’t tell if this was a switch loop or how it was connected but be aware that white is quite often a switch leg or loop where white carries the power to the switch. To give more information on how to connect things properly we will need to see the connections at the switch(s) and we need to know which cable provides the power. If you took photos prior to disassemble i it that could be quite helpful also.

Answer 2

Can anyone tell what is going on in this box?

Actually, no. Not without a fair amount of above-average-amateur sleuthing and a great deal of measuring and testing, which must be done on-site. We can't redpill you on this, at least not in any time-scale one might consider reasonable lol.

As you can see, wires are NOT color-coded in any useful manner. The wires aren't color-coding; they're how cables are made: /2 has black+white and /3 has black+white+red. It's possible to infer some information because of standards over how white wires are supposed to be used, but it's usually not enough.

**The way one electrician documents the configuration to the next electrician is in how the wires are connected already. 3 blacks spliced to 1 white: we know what that is.

It's a trope around here that a novice separates all the wires, splays them out in a big asterisk, snaps a photo and then asks what they all do. Sadly the novice destroyed that information by separating the wires. To recover from this requires a huge skill leap.

Why are there four plain copper wires?

Those are safety ground. 4 safety grounds is strong evidence that you have 4 cables coming into the box. (supported by there being 4 white and 4 black wires).

Grounds are the one simple thing here. Grounds must all be connected to each other, and to the box if it's metal. Metal boxes will carry ground to lamps and switches; all others must also have a safety ground run to them.

Why is there only one red wire?

Because 2-wire cables are manufactured black-white. (plus a safety ground). 3-wire cables are manufactured black-white-red. (plus ground). Conclusion: You have one 3-wire cable in the box.

So far we know you have one 3-wire cable and three 4-wire cables. This adds to the picture.

The fact that there is exactly one 3-wire cable, and the fact that all its non-ground wires were previously nutted together, is a hopeful sign - it means there might be a "modern" switch loop already installed in the walls, if we can find confirmation of that, it'll identify that cable at least.

What is the purpose of the brown bundle of wires that contains a black, white and copper wire? Is this even safe?

I would certainly hope so! That is "NM" type cable. Cable is several individual wires attached together, typically inside a sheath, but not always.

The brown sheath may just be a brand/style, or it has aged, or it's from fire damage.

Also, is it safe to attach this very simple light fixture to it once the fuse is replaced?

Wait, fuse???

Once the various wires are identified and their purpose is determined for certain, it may well be possible to put a light here. You certainly can't blow past that 'identifying' part, if that's your hope. This will require a GREAT deal more skill than you have so far.

It's certainly possible to attain that skill, but this won't happen overnight. Given the complex task of analyzing this 4-cable network, the only fast way is to hire a pro.

Answer 3

I'm a pretty competent amateur in this area, so I'll tell you what I would do if I encountered this in my own home. The main reason for my post is to help you decide whether you may be in over your head on this project. A licensed electrician would figure this out faster, and maybe cheaper, than an amateur like me.

So, the first thing I would do is turn all the switches in that room to the off position, and measure for voltage among those ground wires and all of the other wires -- to determine if any have voltage when the switches are off. Hopefully they don't, and if they do, your troubleshooting will be more complicated -- there may be a 3-way or switched neutral involved, or more likely, the switches for this light are supplied from this J-box via switch loops.

The tool I'd use to measure for voltage is a volt-ohm meter -- if you aren't comfortable using one, this is a sign the learning curve for this project may have an extra skill (and expense for a new tool), but it will come in handy later.

I'd then toggle each switch and re-measure voltage among the potential hot/neutral wires to find out what each switch does in relation to the wires in the box.

As you're performing these tests, write down what's happening with the wires in the box so you won't forget.

Once you finish doing this, you will probably know how to re-connect the new light/fan. If you don't, update your post here with the information you gathered. Note that if it's still confusing at that point, you might also end up pulling the switches out of their wall-boxes (temporarily) to measure some things there, too.

Finally, let me note that the problem you are encountering right now is exactly why the electrical code forbids re-purposing white wires for things other than neutrals. It may have been legal when the light was originally installed, but you couldn't legally do that today, because the folks behind the electrical code realize homeowners (and pros) in your situation shouldn't have to play a guessing game about what all those wires are doing. If you ever thought, gosh, building codes; well, they're actually a good thing almost all the time. :D