Old wire thicker than new wire? (2023 Update)

I've come across some wire that is probably 30 years old and is marked

14 gauge. The minimum gauge I want snaking around the house is 12 gauge, so I was about to pull it out when I noticed that the copper is about as thick as new 12 gauge (and thicker than new 14 gauge). Is the copper thinner now because of improvements in the manufacturing process, or something? Is the wire rated by thickness or by current carrying capacity? If it is current carrying capacity, then are they using thinner wire because newer copper is a better conductor? This isn't the plastic insulation I'm talking about, it's about the copper itself.
Reply to
Nexus7
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Gauge is actually a measurement of thickness, just like inches and feet are a measurement of length. I don't think it has ever changed. Did you put a gauge measuring tool on both?

Reply to
Bob

It appears markedly thicker visually, but I'll use a vernier this evening. I just thought they might be selling thinner wire rated for the same capacity, kinda like they sell something 1.5X3.5 and call it a

2X4.
Reply to
Nexus7

12 gauge can be a bitch to work with, especially when you need to cram it behind the switches in boxes that aren't big enough. Are you sure you want it running EVERYWHERE in the house?
Reply to
Doug Kanter

cant go wrong running 12 gauge, but it is hared to work with. I wonder why they dont make boxes bigger, that would help a lot.

its likely the same conductor size but old wire used real rubber coverings, that were thicker. that may explain the confusion

Reply to
hallerb

Maybe the "thicker" 14 ga. is stranded, and the thinner 12 ga. is solid?

Greg Guarino

Reply to
Greg G

"12 gauge can be a bitch to work with, especially when you need to cram it behind the switches in boxes that aren't big enough. Are you sure you want it running EVERYWHERE in the house? "

It's not a bitch to work with if you use stranded wire.

Reply to
scott21230

Stranded wire for house wiring? I didn't know that existed.

Reply to
Doug Kanter

All romex (nm) and armored cable is solid. I have NEVER seen any type of stranded permanent electric wire used in a house.

I did also notice that it appears older wire was thicker than todays comparible cable.

As for 12 guage being a pain in the ass to work with??? Bah! you'll get used to it, just like anything else. I rather have the higher compacity cable in the walls just in case I want to go 20 amp rather then having to rewire when all the walls are up.

Tom

Reply to
BocesLib

Smaller boxes are harder to work in. More difficult = more manly man, or some such bullshit. That's the only reason I can figure out. Code dictates that as you run wires along beams, you don't bend them more than a certain amount. Keep the bends gradual. Then, code says it's OK to jam the wires into boxes in a way that doesn't match the previous rule.

Reply to
Doug Kanter

I believe that there was some copper clad aluminum wire used for house wiring a while ago.

Aluminum has only about 70 percent of the conductivity of copper. If what you found is copper clad aluminum then it makes sense that it's a bit larger in diameter, but marked 14 gauge because it has the same current carrying capacity as 14 gauge solid copper wire. Try filing on the wire and see if you get down to aluminum.

If that's not it, then I'm gonna make a WAG that if your vernier shows the older copper is in fact solid copper and of a larger diameter, the difference may be because the newer insulation materials can withstand a bit more heat than the older stuff could. So, they can dissipate a few more watts in resistive losses without danger of the insulation going up in smoke or falling off. But that's a verrrrry WAG I theenk.

Jeff

Jeff

Reply to
Jeff Wisnia

Old Romex Type NM used type TW conductors. New Romex Type NM-B uses THHN conductors. The insulation is thinner but the conductor itself is the same size.

Reply to
gfretwell

I have been in the "trade" for 35 years, American Wire Gauge has not changed it that time. 12 is 12 and 14 is 14. What has changed in romex is that some manufactures A LONG TIME AGO made romex with 12 or 14 conductors and a reduced ground ~16awg. These cables were produced before I started buying wire.

Reply to
SQLit

Reply to
Rusht Limpalless

ONe is not supposed to make sharp turns in cable tv coax either**, but then the cable folded the cable twice and stuffed it in that little box outside my house. It annoyed me.

**That because the insulation between the center wire and the braid can be compressed, and the distance between the two becomes less, and that can cause signal reflections and ghosts in the picture. I think the picture was good though. I'm not too picky. :)

Remove NOPSAM to email me. Please let me know if you have posted also.

Reply to
mm

That's what's typically run inside conduit.

Reply to
Doug Miller

Stranded is not code [NEC]. A good home inspector should catch it and required it's replacement before getting an occupancy permit.

Reply to
Jay Stootzmann

Yeah, try some 500 MCM copper if ya wanna wrestle some bear.

Reply to
volts500

Conduit? Hard pipe conduit? Or, other?

Reply to
Doug Kanter

Cite that.

Reply to
gfretwell

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