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ceiling light basic electrical question

Posted by elalbino63 (My Page) on
Wed, Oct 19, 11 at 14:22

Hi:
I had a ceiling light in the kitchen. I noticed it was flickering and the socket wires on one side were fried. I got a replacement from lowes and it should be pretty straightforward but I noticed there is a black hot wire and a wire pigtailed from a tan wire in romex.

Ok the pigtail also has a bare ground wire in the pigtail. It seems to me that when the circuit is completed at the least the bare wire would be hot.

The house is a 1930's that has had a lot of work done over the years. most of the wiring is actuall the cloth covered stuff. Ill try to take a pic later but does this seem right? maybe the cause of the flickering and fried smaller socket wires?


Follow-Up Postings:

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RE: ceiling light basic electrical question

here is a link to pics
thanks!

Here is a link that might be useful: electric pic album


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RE: ceiling light basic electrical question

It looks like you have two white wires (now tan) feeding your light fixture. They've obviously discolored due to heat and age. The one white wire that's not connected to a wire nut is probably the "hot" coming from your switch. What I can't tell is what is taped to that wire. Whatever it is, it isn't right. Secondly, the bare ground wire should NEVER be connected directly to the neutral (white) wire.

As bad as this is, flickering (of an incandescent bulb) is usually caused by a loose connection. That also can cause heat build-up, which could be the cause of the discolored wires.

To fix this, I would recommend:

1. Connecting all of the ground wires together, and connecting the ground to the proper place on the new fixture.

2. Replace the broken wire nut, and make sure that all of the connections are tight.

3. Remove that tape and whatever from the switch wire.

4. Inspect the remaining wires to make sure that the insulation is acceptable. If the insulation is cracked or brittle to the point of failure, you'll need to replace the wires.

5. Mark the last inch or two of the wire coming from the switch with a black magic marker to show that it's hot.

If any of this is confusing, it might be time to call in a pro.


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RE: ceiling light basic electrical question

pretty sure the tape is there to tell the last person that was the hot wire. I am thinking since this house was built in the late 20's that it never had a grounded system and someone grafted this into the existing system. man it seems if they did this to this one, if they did it to another then all the plugs that have ground wires (some do not) the ground wires may have voltage when the switch is turned on.

how did it keep from throwing a breaker when the switch was turned on? were they just lucky the bare wire didnt ground on anything.

Maybe whoever did just did it in the one place and got confused about what to do with the bare wires. there are 2 other romex type wires in the box and they are connected together. I understand what you are saying and it makes sense if everything else is normal.


I might have an electrician come out and check the whole system out. the guy that lived here before told me he was a contractor. yikes


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RE: ceiling light basic electrical question

The tape could be a marker for a hot wire, although it's usually wrapped in a spiral pattern around the wire. On the picture it looks like the tape is holding something white with arrows. Could just be my eyes.

The ground attached to the white bundle wouldn't affect the circuit breaker. The problem is that under normal usage, the ground wire shouldn't carry any current. With this set up, assuming the ground wire is connected to the circuit breaker panel, the ground wire would carry some of the current.

The bare wire IS the ground, so it touching some other part of the electrical system that is also grounded wouldn't be a problem. What would be a problem is when a person touches that bare wire and provides a better path to ground than the wire. Then the current is flowing through a person, and that's not good.


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RE: ceiling light basic electrical question

"although it's usually wrapped in a spiral pattern around the wire."

All you have to do is mark the wire.

HOW it is marked (beyond 'permanent') is not in the NEC.


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RE: ceiling light basic electrical question

I got some more of the wire pulled out. There are 3 pieces of romex type wire spliced together. Like they had one continuous wire they cut it spliced another to it put all the black wires together. the romex going to the switch goes to the switch as black and returns as a switched white wire. (the one with tape on it) btw there are some arrows on the end of the tape.

That leaves the 2 original neutral wires. One neutral has voltage according to my tester. The other 2 ground wires are twisted together. does that make sense?

guess I should take the ground wire attached to the neutral and hook it with the other ground wires?

it seems like they took the ground wire from the romex to the switch and purposely connected it to the neutrals when the other 2 ground wires were twisted together right by it. is there any method to that madness?


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RE: ceiling light basic electrical question

A neutral won't typically show voltage as part of a circuit. However, if you disconnected the circuit, and measured the voltage between the neutral and ground, then you're really measuring the voltage across whatever load is present. That's not a problem.

I don't know why the person connected the ground to the neutrals. I suspect that there isn't a proper ground back to the panel, and the installer wanted to pretend that this would take care of the problem. Regardless, it's a code and safety violation.

To fix this might require some replacement wiring. You probably want to check out all of the connections in your house.


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RE: ceiling light basic electrical question

"There are 3 pieces of romex type wire spliced together."

If these splices are not in junction boxes it is a real hazard.

You also need to be careful about what tester you are using.

Non-contact testers (do not need to touch a conductor) and digital meters can give all sorts of 'phantom' readings, showing voltage when none is actually present.
The only clue may be that the meter shows an odd lower than normal voltage.


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RE: ceiling light basic electrical question

Looks like a standard switchloop where someone accidentally put one of the grounds with the neutrals. Just put all the grounds together and attach the new fixture with the marked beige wire going to black and the unmarked beige wire going to white.

Of course, when you see something goofy in one place, it makes you wonder what else is hiding. Personally, I would open up a few more fixtures and see if the whole house was done that way or if it was an isolated error.

"is there any method to that madness? "

No. Both the neutral and ground are actually both path's back to ground. However, they are kept separate so that the neutral is used as part of the normal circuit operation and the ground is kept free as an alternative path for electricity to travel if anything goes wrong. If you combine the 2, you lose that important safety backup path.


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RE: ceiling light basic electrical question

Ok I did just that. Hooked the grounds all together, the black fixture wire to the hot taped wire and the 2 neutrals with the white on the fixture.

Now comes the big problem...

The light doesn't light up. it has 3 separate sockets on it 3 white fixture wires together with the 2 neutrals from the ceiling box. 3 black fixture wires to the taped hot wire.

I think I see why they hooked the ground wire in there. Ill bet there is no neutral to the breaker box. Could they have been using the ground as a neutral?

The tester I have beeps at the fixture sockets with the switch on. Also I have another ceiling fixture with a ceiling fan and a wall socket that are dead now. The attic has been changed to living space above the fixtures.

man I see a big problem. I have a home warranty but Ill bet it doesn't cover incompetence.


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RE: ceiling light basic electrical question

Before you panic, check the switch. It should have the tan wires going to both terminals and the ground to the ground screw.

BTW - it looks in the last picture like that ground mixed with the neutrals was coming from the switchloop and couldn't have been providing a path back to the breaker.


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wiring

I looked at the switch and cloth wires to it. so I guess they hooked to existing wires somewhere. And there is no ground with the cloth wires to the switch. So the way I see it that ground wire that was in with the neutrals could be hooked to anything. I also noticed the tester is actually beeping with the switch on or off.

what do you think?

ps I actually have a decent MM its a fluke 113. I have just never used it on AC before just ohms on stereo speakers.


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RE: ceiling light basic electrical question

"Input Impedance (Nominal) ~3 kΩ"

That is actually a very low impedance for a digital meter, most are well into the 10s of megaohms.


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RE: ceiling light basic electrical question

If I understand you correctly, the wires at the switch are cloth-covered, with no ground. Then, at the light fixture, you have Romex (plastic) cable with a ground. That says that there's a splice somewhere between the two. To be safe and to code, that splice has to be made in an accessible junction box. Any chance there's such a box, perhaps in the attic?

This sounds more and more like something that you want to get a pro to check out.


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RE: ceiling light basic electrical question

no the attic is about 1000sqft converted living space. they did a pretty good job and it too. I guess the carpet could be pulled back and cut into the floor.

Could the prob be a bad/loose wire at the fuse box.

I dont think that anyone that would stick that ground wire where it was would worry about a junction box.

I just got it to check the drivers on speakers. I managed to repair quite few horns and tweets with it.

so the mm is ok to use on this?


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RE: ceiling light basic electrical question

I think your Fluke 113 may be leading you astray.

The 113 has a very low impedance input (less than 3k ohms) to help eliminate reading phantom voltages that often occur with traditional digital meters. The problem however, is they created this in conjunction with what Fluke calls "V-Chek" and something I personally don't care for big time. If the voltage it under a certain level, I think 3 volts, it automatically goes into a Continuity Test Mode and does the "Beep" thing if it detects continuity.

So, if you are measuring the lamp sockets with the switch turned on and it beeps, it means you have continuity between what should be the two separate conductors - hot & neutral.

Sounds like the wires at the fixture are now somehow connected to either side of the switch. You really need to figure out where each and every wire in that box comes from and where it goes.


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RE: ceiling light basic electrical question

I havnt actually used the meter. I have been using a pencil looking thing from lowes that flashes and beeps.


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RE: ceiling light basic electrical question

I don't understand why we're talking about meters here. The problem is that neutral wires are connected to grounds, and there are likely wiring splices not contained in approved, accessible junction boxes. Finally, there's at least some evidence of poorly made connections, causing heating problems and flickering of the lights. None of these issues are related to the type of tool you're using.

These problems need to be fixed.


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RE: ceiling light basic electrical question

Hi! When I look at the two last pictures, it seems to me that the white wire with tape comes from the same Romex as the bare wire connected to the other neutrals. If that's the case, they probably extended the circuit from a switch loop, using the bare copper wire as a neutral.

If you remove the switch for that fixture, do you see that bare copper wire connected to another wire, probably a white wire? If it's the case, it is very dangerous and should be addressed immediately, probably by replacing the Romex between the switch and the fixture box with a new length of 14/3 or 12/3, using the black as the hot, the white as neutral and the red as the return to the fixture.


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RE: ceiling light basic electrical question

The wires in the switch are cloth covered so the splice is inbetween the switch and the fixture. Its not visable what they did. Even if I check the wires I cant trace them and dont know how to replace wiring without tearing a lot of ceiling (or floor upstairs) up.


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RE: ceiling light basic electrical question

and dont know how to replace wiring without tearing a lot of ceiling (or floor upstairs) up

That's how you rewire.


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RE: ceiling light basic electrical question

I had another old house. that one was built in 1933. It had metal conduit all throughout. I got the whole thing rewired. they pulled wire thru the whole house. I haven't seen a single conduit in this house built a few years earlier. guess they did it differently. or the conduit has been cut out.

I guess you cant pull romex thru whatever. thats a shame


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RE: ceiling light basic electrical question

"and dont know how to replace wiring without tearing a lot of ceiling (or floor upstairs) up"

Or you learn how to fish wires between access points to minimize damage.

You do not have to follow the route of the existing cables, and in many cases may actually take a longer path to minimize wall damage.

It does take more time tan simply hacking holes in walls and ceilings willy-nilly.

With careful planing (you may need to do more damage to a single stud bay wall to minimize damage elsewhere), planing, and 'tricks' wall damage can be minimized at greater cost for the electricians time.

Drywall is easily enough repaired to not usually be worth a large effort unless you have a texture that could be hard to duplicate.

Plaster walls are often well worth minimizing damage, since in some places even finding someone to do a repair is very difficult.


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