NM cable in the basement

I have an old house, built in 1926, that could use some repair work (no surprise).
In the basement, part of the junctions two junctions in which lightbulb outlets were installed in tiny, circular junction boxes. I recently removed them, and installed larger boxes with outlets instead. The real issue came when trying to put the rigid metal "conduit" back in place. I put conduit in quotes because I think it is really old water pipe used instead.
Because the junction boxes are larger, the conduit connecting the two pushes them further apart, making for a very klutzy install. I would like to replace the rigid conduit with flexible, giving me more, err, flexibility in the install.
Here is my problem. Because I am home repair newb, I had never heard of NM cable before. From what I have read about it, it looks much easier to work with, and, therefore, is right up my alley. The cable connecting the junctions will be running along the top of the basement, out of reach of heavy people traffic. However, my house has no grounding wires, it is only hot and neutral (110), and it can get relatively more damp in the basement than the rest of the house. Given this, can I use NM for this purpose? Am I violating code? Is there some serious risk associated with it that I should be aware of? Any help would be greatly appreciated.
TIA, hbchrist
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hbchrist wrote:

Your house probably *does* have a ground, the existing wiring doesn't. NM-B (which is what you'll get by default) is just fine in damp enviroments. If you are really concerned, look for "NM-C". Collectively, the are commonly called "Romex", which is probably a brand name. Way overkill would be "UF" cable, but don't use UF because it is so difficult to work with. The NM cable has a ground wire, and you really should find a way to connect it back to the electrical panel. If you are replacing an entire old circuit with new cable this is easy. If you are just tying into the old wiring at a junction box, it sometimes takes a little ingenuity. When upgrading old work, the safety ground wire should be run with the current carrying wires, but it doesn't have to if it's impractical -- you can run a separate ground wire from the junction box back to the panel or to a grounding electrode conductor.
The main panel or the electric meter is probably wired to the water pipes with a big bare copper wire. This is your grounding electrode conductor (the house ground) Make sure there is a big wire jumpered around the water meter. You should probably add a second big copper wire from the panel to a couple of 5/8" copper-clad grounding rods space 6 to 10 feet apart if there's not at least one rod already.
Best regards, Bob
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You are probably right on the ground, I am nearly positive that it is grounding near the water main in the corner of the basement. THe area is dirty, so I have to clean it off considerably to be sure that it is what I think it is.
The wires running through the pipe are, I have since learned, "warly NM". Each wire is coated in rubber then cloth(?), and only two are in there, one black, and one white. Every other place in the house where I have replaced switches and outlets (or installed GFCI outlets), has this same setup. From what you and l-zheet say, however, I should be good to go with moden NM. Upon reflection, I should probably put GFCI outlets in the junction boxes instead.
The switch box itself is thoroughly modern. The gent from whom I purchased the house had the entire thing replaced with modern circuit breakers and a nice panel about a year before he sold the house. Bummer he didn't upgrade the wiring.
Thanks again, hbchrist
zxcvbob wrote:

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hbchrist wrote:

If that's the case, you likely have an old fusebox that is grossly undersized for modern electrical demands. That, along with the old non-grounded wires running through water pipes (Does one particular Three Stooges episode come to mind? It should! <g>) means you should REALLY consider getting a new service installed, all the way from the point where the power company connects, all the way through the meter base and the breaker panel to the first junction box on each circuit. At least then you will have a safe, modern, up-to-code place to start in on the DIY rewiring. Many electricians out there market this as a "package", it's not like they don't see your situation often.
If you can't do that, yes, you can use Romex in your basement, pending approval by *local* building/electrical code. The NEC allows "exposed" wiring in unfinished spaces like basements and attics, but make sure your municipality doesn't have some overiding "gotchas" hanging out there, you would hate to have to rip stuff out after you've worked on it.
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Rigid conduit is very similar to water pipe, in fact it is just a lighter weight (schedule 10 vs 40 or 80 for water pipe).
Water pipe is perfectly usable for electrical (if you have a hydraulic bender<G>) in heavy abuse situations. The most common usage I've seenis outdoors, to hold up boxes, where the extra strength is handy, or to run down a wall, where it gets it by lawn mowers and the like. The inside diameter is smaller so it reduces the amount of wire that can be fed through it.
In a basement, probably overkill, unless your doing something like a chainsaw art studio, and you need way above normal protection.
Iron pipe is iron pipe, you can put anything it that needs the strength of the material.
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John Hines wrote:

Not to mention it can make Niagara Falls gush out of your TV set and your poor bug-eyed cook/servant slip and slide all over the kitchen! <g>
OK, seriously: Understand everything you're saying, I just doubt anybody was hanging conduit in this basement 80 years ago, which leads me to believe that it really is iron pipe, or maybe galvanized water pipe?, and that gets us to that "overkill" thing. Somewhere there's a dumpster crying out for all of that pipe, after the OP uncomplicates his life and re-wires it all with simple NM.
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Probably rigid conduit, which looks just like water pipe, but with a thinner wall, which is hard to tell unless you work with it all the time.
My preference is to have surface mounted boxes, connected with conduit. I'd don't bend the conduit so it is flat against the wall, so it is a handy place to stick stuff on short notice. Not code, but handy. The outlets run around the wall, not on the ceiling.
I've repulled the wires a couple of times, as I change my mind on what I want to do.
I "like" the idea of metal protected wiring in a workshop, it looks and feels "shop like".
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John Hines wrote:

I am inclined to go with the belief that this is cast iron plumbing. It's thick walled and very heavy. I could kill with this stuff. Not that I would, of course, I'm just saying.
To l-zheet's point, it is coming down and I am going NM. Makes life a lot easier and lets me do all sorts of interesting things downstairs.
Regards, hbchrist
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