which wire is which -HELP!!!


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Old 08-16-08, 10:49 AM
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which wire is which -HELP!!!

Hi-
The project I am working on changed a bit due to the cost. I had originally intended to replace teh wiring in the entire living room, but now I have to leave the ceiling light wiring in. It is just too costly to replace that one wire.

Because I had intended to rip out the old K&T wiring, I didn't label anything. I know, I know.

Now I have 2 wires coming out of the wall that used to power the ceiling fan/light. I have a new switch recepticle wired in as well. I need to make sure I am conntecting the right wires.

See below for my multimeter readings and an explanations of the wires:

Wire 1 - Old Wire
Wire 2 - Old Wire
**Not sure which is neutral and which is hot, if I did, I wouldn't be here now

White
Black
**New Wires roughed in the wall from new wiring.

Wire 1 + White - Nothing
Wire 2 + White - 115
Wire 1 + Black - Nothing
Wire 2 + Black - 240

Wire 1 + Wire 2 - Nothing
Black + White - 115

It is the 240 one that makes little sense to me.

Any help would be great. If I need to to any other tests, I can.
 
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Old 08-16-08, 11:17 AM
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A non-contact voltage detector can tell which of the old wires is hot or you can test for voltage between each wire and a known ground. An extension cord can help you here.

Old non-grounded circuits are not supposed to be extended.
 
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Old 08-16-08, 11:21 AM
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Wire 2 is your hot. That is why you are getting 240 volts. Your leads are on two hots on different phases
 
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Old 08-16-08, 12:06 PM
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so what do I do to connect all the wires?
 
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Old 08-16-08, 01:36 PM
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NO! Do not connect all the wires together! You will blow stuff up for sure. If I understand this correctly you have K&T coming down from the ceiling light/fan and new wires for switched outlet. I'm guessing the K&T is a hot and switch loop. That is why you get nothing between them. Connect those 2 wires on one switch. One per screw.

How you connect your new wiring will depend on how it was wired. You now have a hot and a neutral so you should also have a cable going to the outlet you want switched (perhaps a 14-3) connect the hot (black) to one screw on your switch. Connect your switch leg (black or red if using 14-3) which will be the cable going to the switched outlet, to the other screw. If you used 14-3 then also connect the black going to your switched outlet to the hot in your switch box and pigtail the hot to the switch.
 
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Old 08-18-08, 08:47 AM
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OK so it liiks like I will connect the neutral and hot to the switch. I will do some continuity testing to make sure all the wires are good.

I will essentially be re-building the switch the same way it was before I cut the wires. I never had a problem with the fan then so everything should be hunky dory.

Questions for this.

1. Since I cut the wires short I cannot put a switch between them without extending the wires. I have to lengthen the wires. I have to do this in a j-box, i get that, but what kind of wire do I use that I can keep in the wall? It will only be one wire in each junction. Can I use THHN?

2. I already have romex pulled to where the switch will be. I will not be using the hot or neutral for the light since the old K&T hot is still active, but can I use the ground to ground the outlet? My brain is saying it will be safe but probably against code.
 
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Old 08-18-08, 10:39 AM
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Emo,

I hate to be blunt but it seems like you are totally over your head on this.

Neutrals are not connected to switches with hot wires. Doing so creates dead shorts. You don't seem to grasp this important issue.

You have been told how to identify wires and the possible connections to make to solve your problem and you are still no further. I suggest you get some professional help solving this.
 
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Old 08-18-08, 10:42 AM
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OK so it liiks like I will connect the neutral and hot to the switch. I will do some continuity testing to make sure all the wires are good
Not really. You never connect a hot and neutral to a switch. You will be connecting a line hot and a load hot to a switch. You can't by code extend K&T wire. If they're too short you probably can by code use them.
 
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Old 08-18-08, 01:30 PM
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Originally Posted by pcboss View Post
Emo,

I hate to be blunt but it seems like you are totally over your head on this.
I think you might be right. I'm having my stepdad come over anyway (he's an electrician) I just like to have some idea about what I'm talking about before I waste his time. Makes for better bonding and I feel more responsible doing research before I ask for help.

He's belssed every other electrical update I've done in the house before I turned the power back on.

THis one was just trickier than those.

Thanks

I also think I use the wrong terms, which doesn't ever help either...
 
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Old 08-18-08, 05:22 PM
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Use this as a learning experience. Let your step dad explain what you were looking at and the proper terminolgy. Ask him to explain basic circuitry.

This can still be a positive time. Bond by learning from him while you spend time together.
 
 

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