Replacing 1940's wiring

Old 08-08-03, 07:10 PM
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Replacing 1940's wiring

Sorry for the length of the post, I appreciate replies from experts and others willing to read the whole thing.

I recently moved to a charming cape cod built in 1942. My first project was to hang a ceiling fan in a bedroom, and as I took out the old light and checked out the support for the box, I noticed that just moving the wires around a little, the sheathing covering them kind of peeled away like string. I was left with bare metal, copper on the inside with a coating of gray metal, (must be a World War II conservation thing). I suppose this stuff is fine if it never gets moved. I also found that almost all of the lights and outlets are on only three circuits, since 60 years ago they weren't running all that much stuff. Other double breakers are used for stove, dryer, and a recently-removed room AC. So I decided to tackle one of the circuits and just replace it all with good ole' NM- B with ground. I was able to get to most of the boxes through the walls either from my unfinished basement or almost unfinished attic. A couple holes in walls were needed; those can be patched anyway. I'm about ready to connect the new wiring to the panel, which I've never done before, and figured I'd ask a couple of questions just to be sure I'm okay. (I've invested three days already, and dear wife is getting tired of half the house being out). Here are three questions, numbered for easy reference on replies:
1) Since I can't get inside the walls to attach the cable with staples next to the box, I just made sure they were snugly clamped in the 1940's style metal boxes. I could still staple where I went up or down through attic/basement. Is that good enough to secure them inside walls.
2) If I have three cables in a box with an outlet, can I use both the side-wire and back-wire (push in) terminals on the outlet. That way I won't have to connect with a wire nut and pig tail to the outlet. The boxes are not that big and I'm concerned about space and code requirements for items in each box. I really don't want the mess of brand new boxes.
3) Since I've never connected to a panel before, are their any tricks beyond what I've read in the normal handyman books? (I think Time-Life had a good description). I suppose I just turn ff the main breaker, change the new cable for the old through the same hole in the panel, and connect everything the same way it is now. I'll have a ground wire on the new cable, which the old didn't. I thought there would be a bus for the ground, but I see the newer grounded circuits terminating on the neutral bus bar. So I guess the neutral and ground are the same?

Any other things I should think about before going live with this circuit? I'm fairly confident about my connections to switches, fixtures, and outlets, I've done them before and the books are helpful. The real pain was that 60 year old wires don't have nice little black, white, and red that are easy to distinguish, after disintegrating for half a century.

Old 08-08-03, 09:10 PM
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(1) Staples are not required for cable fished through finished walls.

(2) Yes, you can. But I would strongly recommend against it. Those push-in connectors are very unreliable over the long haul. If there aren't enough screws, use pigtails.

(3) No special trick as long as you know that shutting off the main breaker does not remove all danger. Run the wires neatly, and make the connections very tight. In a main panel, neutral and grounding are electrically equivalent. You will probably need to buy a grounding bar kit (about $5), since you will run out of space on your neutral bar and you don't want to double-up.

Since we don't know what you've already thought about, it's hard to say what else you should think about. If you've done your homework well, thoroughly reading several books on home wiring cover to cover, you should be fine.
Old 08-09-03, 09:15 AM
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Your wife should be VERY proud of you for what you've accomplished in a brief time-period------Good Luck!!!

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