Installing a light fixture- need a little help before I burn down the house


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Old 10-25-13, 08:17 AM
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Lightbulb Installing a light fixture- need a little help before I burn down the house

Hi everyone, I recently bought a house (built in 1901) in Brooklyn NY. The light fixture in the entrance hallway is ugly as sin, so this past weekend the wife and I bought a new one. I figured it would take an hour or two to swap the old fixture for the new one. Here I am 5 days later still trying to figure it out.

The hallway light that Iím replacing is controlled by a single switch. Iím replacing a hanging fixture with 4 bulbs to a hanging fixture with 1 bulb. When I removed the old fixture I was greeted by a nice tangled mess of old cloth-covered wires, in an old junction box unlike one I'd ever seen. I expected to see maybe three wires in the junction box, instead I've got 7. I used a non-contact tester and from what I see there were 3 hot wires grouped together in a wire nut (not connected to the old fixture, and not affected by the light switch on the wall); there were three neutral wires grouped together in a separate wire nut (connected to the neutral wire of the old fixture), and there was one more hot wire attached to the fixture's hot wire (this one is turned on/off by the switch on the way). Nothing is color coded as this is old wire. Also there is no ground wire. The old fixture did have a bare copper wire running down its chain, but I donít believe it was attached to anything in the junction box. FYI the new fixture doesnít have a ground wire at all.

The new fixture wouldnít fit onto the old junction box due to the shape and being no place to attach a cross bar, so step 1 was to remove the old junction and replace with a new one. Due to the space available I had to use a 1/2" deep ďpancakeĒ junction box. I replaced the box, and reconnected the wires as they had been. I tested again with a non-contact tester, and again everything seemed fine. One of the hot leads only shows current when I turn the switch on, the other three hot leads always show current even when the switch is off, and the remaining three wires show no current at all. I then used a circuit tester- when I touch the junction box with the testerís negative wire and touch a hot wire with the positive, the tester shows me 120V. The same happens if I touch the hot and neutral wires.

I then attached the fixture. The neutral went to neutral and the hot went to hot. I even double-checked these with a continuity test- the hot wire is connected to where the light bulbís tip will be, and the neutral is where the outside threading of the bulb will be.

When I turned on the light it doesnít work. MORE IMPORTANTLY when I put the non-contact tester next to the fixture itself it lit up and beeped. So unless Iím going crazy there is actually currently going through the metal OUTSIDE of the fixture, i.e. the decorative canopy covering the light. Iím not seeing current in the chain from which the fixture is hanging. I immediately shut off power again at the breaker box, removed the fixture, and checked connections. Again everything seems OK. Iím not seeing a short (using a continuity test) between the hot wires and the junction box, or between the hot/netural wires, etc. Not really sure what to do from here. Can the fixture itself be broken?

Any help or insight is appreciated.
 
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Old 10-25-13, 09:29 AM
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Sitting here at work waiting for someone (ANYONE!) to respond and something just occurred to me that may be involved.

Like I said there were 7 wires in the junction box. Why the odd number? I'm remember now being confused about this. There were basically 3 metal-armored cables running to the junction box (AC/BX cable). Two of the cables had two wires inside. The other had 3 wires. So I think I messed up. The two BX cables with two wires are clearly hot & neutral. But I'm guessing the one with three wires is hot/neutral/ground. Does this sound right?

I treated ALL wires without a current (as detected by the non-contact tester) to be neutral. I therefore connected them all together in a wire nut to the neutral wire on the light fixture. If I'm correct though, then I ended up connecting that one ground wire, which I'm reading is a big no-no.

If it sounds to you like I'm on the right path to an answer...how do I determine (in the BX cable with 3 wires) which of the three is neutral and which is ground? And where would I attach the ground wire, because there is no bare copper wire in the new fixture. Would I attach it to the ground screw on the junction box?
 
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Old 10-25-13, 09:50 AM
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I treated ALL wires without a current (as detected by the non-contact tester) to be neutra
Non contact meters are not a reliable way to determine if a wire is hot. A wire not white will not be a neutra.
'm guessing the one with three wires is hot/neutral/ground. Does this sound right?
No. A red ,black or white wire will never be a ground. Most likely would be white is neutral, black is unswitched hot and red is most likely switched hot. Most likely the two 2-conductor cables carry power to other fixtures. However before continuing you need a accurate way to check for voltage. A cheap $8-$15 analog (not digital) multimeter would be a good choice. Or just hook the light to the white and red of the 3-conductor cable and see if the switch turns it on and off.
 
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Old 10-25-13, 11:58 AM
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Thanks for responding Ray. Unfortunately there are no colors on any of the wires.
 
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Old 10-25-13, 02:08 PM
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Unfortunately there are no colors on any of the wires.
Sorry your post was so long I just skimmed it. I should have read more carefully. With what you have I would suggest an electrion because it is a complex problem not easily solved over the internet. It requires making assumptions that then must be proved true or false. Read on for my assumptions for the first test. My assumptions may prove wrong.

At the 3-conductor cable using a multimeter measure between each wire and ground (the metal box) with the switch off. The one that shows 120 volts switch off label black. Test the other two with the switch on. If one is hot with switch on mark it as red. The third wire should be white your neutral. Finding which is black and white on the other two wires will require determining where they go.

However the big problem which must be fixed first is you can only have two house wires and two fixture wires in a pancake box.
 

Last edited by ray2047; 10-25-13 at 04:37 PM.
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Old 10-25-13, 03:48 PM
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You are also likely over your wire fill on your pancake box.
 
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Old 10-25-13, 04:36 PM
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You are also likely over your wire fill on your pancake box.
ECHO...Echo...echo...
 
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Old 10-26-13, 10:55 AM
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Bah... sorry Ray. Skimmed your post.
 
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Old 10-26-13, 11:48 AM
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bah... Sorry ray. Skimmed your post.
<lol>

. .
 
 

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