AC Wiring "Junction" for Ceiling Lamp

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Old 06-04-15, 01:41 PM
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Question AC Wiring "Junction" for Ceiling Lamp

Long story short, was swapping two ceiling fixtures between houses.

I didn't know which was hot/neutral as the lamps had uncolored wires, learned which was hot/neutral on the lamps- at the other house the ceiling fixture box only had 2 wires (neutral/hot) and a ground.

My house has a mess of wires in the ceiling box (There was a swamp style ac cooler near by the ceiling lamp, maybe old wires from that?)

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The 3-4 black with single white seems to be the switch loop over to the wall and goes to dimmer switch- when I turn the dimmer on or off the single black wire to the far right reads 120v or 0v....so thats the switched hot eh

However 1 of the grouped neutral on the left are hot so since I discovered that I stopped thinking there was a miss wiring.

If a fridge, etc is connected to that neutral branch, and is on when I tested neutral to ground that would explain why I saw 120v on one of the neutrals?

Sort of stopped and waited to make sure everything was alright up there-
 
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Old 06-04-15, 02:06 PM
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If you used a non-contact detector it was probably a false positive.

Your fixture will connect to the single black and the bundled whites.
 
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Old 06-04-15, 02:07 PM
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Depending on the type of tester you're using and how you're using it, your results may be difficult to interpret.

The wiring in the box looks like a straightforward power-in, power-out, switch loop lighting box. The black from the fixture should wire nut to the rightmost single black in the picture, and the white from the fixture should connect to the group of white wires on the left.
 
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Old 06-04-15, 02:10 PM
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I used a contact multi-meter

Just one neutral to ground shows 120v~ in the white bundle however I believe it's tied into the circuit with the fridge or kitchen near by.


So if I unplug *everything* near by, and don't see any voltage on the neutral- everything's goldin?


Thanks btw- been holding off on this for weeks now and I was pretty sure I was getting false reading due to a few things being on.

The houses circuits (mobile home) cover a wide area so I often don't bother with the breaker and just turn off the main outside thus I tested hot/neutral to ground with some things still on.
 
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Old 06-04-15, 02:13 PM
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There is no need to change any splices. Leave the splices as they are and just add the fixture wires as directed above.
 
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Old 06-04-15, 02:15 PM
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When the neutrals are disconnected (isolated) and the breaker is on, you can get a 120V reading. But that doesn't mean the wire is "hot" per se. If you did actually bundle a hot wire with neutral wires you will get a large spark and a tripped breaker.
 
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Old 06-05-15, 03:12 PM
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Thanks guys!

I kept the wiring exactly the same, installed, works fine.

Just for giggles I disconnected everything I could quickly (fridge, microwave, etc) still showed exactly 120v on only one neutral.

Just out of curiosity why does hot on outlet show 120, neutral shows 0v- but this neutral does

but thanks once again ibpooks & pcboss ! Now I don't have to look at the box and wires anymore

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