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View Full Version : What's Up With Copper Wire These Days ????



JoeLee
03-03-2016, 06:46 PM
I had to do a small electrical job at a friends house a few days ago. He bought a small roll of 12 ga romex.
I just couldn't believe how stiff this stuff was. I could hardly bend the loop to go around the screw with my needle nose pliers.
This stuff was like steel. This isn't the first time I've noticed this. Then trying to push remainder back into the box and screw down the receptacle was a fight to the end.
I've noticed this with other types of wire as well, smaller ga. stuff like plenum wire even stranded stuff is really stiff.
The mfgs. must be cutting back on copper, I'm guessing it now about 10% or less.
I have a few rolls of romex that's over twenty years old and it's way softer and easier to work with than this new stuff.

JL..............

J Tiers
03-03-2016, 06:54 PM
Copper wire is copper wire, there is no percentage involved.

Are you sure it was copper? Try it with a magnet. There have been reports of copper plated counterfeit wire being sold. That would be guaranteed to overheat in use. With solid wire I'd think that unlikely, but.......

It may be that the annealing step is being left out, since it involves re-heating the wire..... more energy cost.

boslab
03-03-2016, 07:36 PM
It's true we had a big roll of 33kv SWA cable in work, they sent me a peice to look at, it was electroplated steel stranded, looking at it you couldent tell, it was correctly stamped up and all the rest.
Dangerous
Mark

bborr01
03-03-2016, 08:58 PM
I think Evan posted a few years ago about getting some copper plated steel wire. Sounds kind of familiar.

Brian

Blue Mule
03-03-2016, 09:28 PM
Copper work hardens easily. Die drawing usually makes it harder than an ex-wife's heart. They're supposed to anneal it afterwards, but corners get cut.

lakeside53
03-03-2016, 09:29 PM
Romex (that's a brand... not a product) is just plain old copper wire. Yup.. 12awg is stiff. The stiffness is simply the work hardening in the drawing process. Heat a piece with propane - it will become soft as butter. Won't help you, but it will rest your mind that it is copper!

JoeLee
03-03-2016, 10:49 PM
Copper work hardens easily. Die drawing usually makes it harder than an ex-wife's heart. They're supposed to anneal it afterwards, but corners get cut. I believe it was some no name cheap stuff from HD.

JL...............

darryl
03-04-2016, 12:46 AM
Definitely take a magnet to it. Copper is non-magnetic to at least the same degree that water is. Even using a 'super magnet', there should be no discernable attraction to copper. As stated, if there is an iron or steel core there will be resistance, voltage drop, and power loss- potentially to the point of overheating and fire, etc. There is no way that a wire called speaker wire, drop cord, lamp cord, romex, nmd, house wiring, bell wire- I don't remember all the names- should include anything but copper in the actual wire itself. The exception might be antenna wire, where physical strength could be the most important factor. Anything meant for power should have proper conductor material. There might be a steel core for strength, but none of that core should be included in the equation for wire size for current carrying capability.

At one point I decided to test some dollar store wire offerings. To this day I carry a magnet on my keychain. I found more than one instance where supposedly copper wire was magnetic. The advertising said 'speaker wire', and nowhere on the package did it say copper. There was also wire advertised as lamp cord, which was also magnetic. Last thing I want to see is lamp cord getting hot running a single 100 watt light bulb. To me this 'copper wire' is fake, and dangerously so.

I won't buy any wire that I expect to be copper without doing the magnet test first. I believe I'm right to expect house wiring to be copper and nothing else. If it doesn't pass the magnet test, it becomes an obligation to me to expose the falseness of the product. I feel very strongly about this- it's dangerous and it's a deliberate deception by a manufacturer.

Maybe what you're seeing is wire that has been alloyed and is stiffer than copper would normally be. Perhaps the alloy is non-magnetic, which now makes it difficult to detect as fake- you'd have to do a resistance test using the length and gauge of wire to determine whether it's legitimate copper or not. It wouldn't surprise me if a significant amount of zinc makes it into the melt, along with steel or iron and who knows what other 'impurities'. I've already seen the fake crap on the market-

lakeside53
03-04-2016, 01:35 AM
Just check the listing or labeling... printed or embossed right on the sheath. I've never seen "fake" copper wire sold as real power wiring, and I've seen a lot of wire in my time.

fastfire
03-04-2016, 03:43 AM
Stranded copper wire bends more easily than solid copper wire. FWIW.

winchman
03-04-2016, 04:20 AM
Here's that thread: http://bbs.homeshopmachinist.net/threads/40772-Major-SCAM-alert!

Black_Moons
03-04-2016, 04:30 AM
Just check the listing or labeling... printed or embossed right on the sheath. I've never seen "fake" copper wire sold as real power wiring, and I've seen a lot of wire in my time.

Ahem.


It's true we had a big roll of 33kv SWA cable in work, they sent me a peice to look at, it was electroplated steel stranded, looking at it you couldent tell, it was correctly stamped up and all the rest.
Dangerous
Mark

From a country that put melamine into baby formula, I highly doubt copper coated steel being sold as house wiring is beneath them.

PStechPaul
03-04-2016, 04:37 AM
I don't think stranded wire is allowed for electrical wiring, at least not for the usual 15-20 amp #14-#12 applications for standard switches and receptacles. The screw connectors and quick-connect spring contacts are probably not designed for stranded.

Here are articles on the annealing process, as well as information on copper with oxygen content that can change its electrical and mechanical properties. Maybe an induction heater could be used to anneal the wire, but the annealing temperature is 700-800 degrees C which is far above the melting point of the insulation. But it might be possible to strip back the insulation and anneal the bare wire, although then you would have to put insulation back on it. Maybe heat shrink?

http://www.copper.org/publications/newsletters/innovations/1997/12/wiremetallurgy.html

http://www.inlandbonsai.com/articles/copper/copper.pdf

Ian B
03-04-2016, 05:01 AM
The only 'legitimate' use of copper plated wire that I know of is in network cabling, where CCA (copper coated aluminium) is often substituted for the much better solid copper. It's cheaper - always good to check for if you're buying CAT5 cable and are expecting solid copper...

Ian

Rosco-P
03-04-2016, 06:36 AM
I don't think stranded wire is allowed for electrical wiring, at least not for the usual 15-20 amp #14-#12 applications for standard switches and receptacles. The screw connectors and quick-connect spring contacts are probably not designed for stranded.

Here are articles on the annealing process, as well as information on copper with oxygen content that can change its electrical and mechanical properties. Maybe an induction heater could be used to anneal the wire, but the annealing temperature is 700-800 degrees C which is far above the melting point of the insulation. But it might be possible to strip back the insulation and anneal the bare wire, although then you would have to put insulation back on it. Maybe heat shrink?

http://www.copper.org/publications/newsletters/innovations/1997/12/wiremetallurgy.html

http://www.inlandbonsai.com/articles/copper/copper.pdf

I don't think you know what you're talking about. Are you a licensed Electrician, Apprentice or Journeyman working under a licensed Electrician?

ironmonger
03-04-2016, 08:17 AM
I don't think stranded wire is allowed for electrical wiring, at least not for the usual 15-20 amp #14-#12 applications for standard switches and receptacles. The screw connectors and quick-connect spring contacts are probably not designed for stranded.
<<snip>>

I seriously doubt that you could find 10 feet of 12 solid on any construction site. The electricians would scrap it out rather than pull it.

lakeside53
03-04-2016, 11:13 AM
Yes, stranded is the most common wire used in non-residential applications. "Romex" is just and brand name that has become common usage for NM or UF type cables.

"Spring type" receptacles or similar are not used on stranded - Commercial is almost always "spec grade" which has either clamp and/or screw type connections.

I use stranded in my house and shop where I run conduit (more and more by the year...).

flylo
03-04-2016, 11:25 AM
I bought some 2/0 & ir came steel wire copper clad for monster auto stereo systems. The idea is that most of the current runs on the outside of the wire? I'm not saying it's true just what I was told when I called about my purchase. It was of course stranded.

ed_h
03-04-2016, 11:27 AM
Many years ago in the Army, we used miles of twisted pair, copper plated, tinned, insulated stranded steel wire called "comm wire". It was strung through trees or even on the ground to set up tactical wired communication system, often including a simple switchboard. The wire was very strong, and the insulation tenacious. The individual strands were like needles when working with it.

Ed

fastfire
03-04-2016, 11:44 AM
I seriously doubt that you could find 10 feet of 12 solid on any construction site. The electricians would scrap it out rather than pull it.

My shop 40"x80" is wired using solid 12ga in conduit.

flylo
03-04-2016, 11:52 AM
My shop 40"x80" is wired using solid 12ga in conduit.

That's not a shop 40"x80" is a doll or dog house!:rolleyes:

JoeLee
03-04-2016, 12:13 PM
40 by 80 inches is a closet.

JL................................

flylo
03-04-2016, 12:27 PM
Or a phone booth. It's a bird, it's a plane, NO it's Machinest Man!

Blue Mule
03-04-2016, 12:34 PM
I bought some 2/0 & ir came steel wire copper clad for monster auto stereo systems. The idea is that most of the current runs on the outside of the wire? I'm not saying it's true just what I was told when I called about my purchase. It was of course stranded.

The skin depth at 60 Hz is about 3/8". That's a radius, so you wouldn't see much effect until you get up to around 3/4" bus bar. Speaker wire is sold in many "special" configurations, but the very best, if you can afford it, is white 18AWG zip cord.:cool:

kendall
03-04-2016, 01:27 PM
The skin depth at 60 Hz is about 3/8". That's a radius, so you wouldn't see much effect until you get up to around 3/4" bus bar. Speaker wire is sold in many "special" configurations, but the very best, if you can afford it, is white 18AWG zip cord.:cool:

I normally pick up a cheap 14awg extension cord when running speakers.

flylo
03-04-2016, 01:51 PM
We're talking HUGE dc car systems please 2/0, I ordered for dc welding cable

gellfex
03-04-2016, 02:27 PM
Couple of decades ago I was developing a low voltage lighting system based on spring temper copper clad wire. Clad, not plated. This wire had like 3x the ampacity of steel, but was immensely stronger than copper. I believe its common use was stringing between poles, due to it's strength it would not stretch. I've still got a 50lb roll of a 1/16 sample run that wasn't quite hard enough, it's terrific for vegetable & grape trellises.

kendall
03-04-2016, 03:33 PM
We're talking HUGE dc car systems please 2/0, I ordered for dc welding cable


and Blue and I were both talking speakers.....

In response to the original post, I recently rewired my kitchen, bath and one wall of my living room with 12 gauge copper. (To replace the old 60s era aluminum.) Normally I carry a small pair of needle nose pliers to make the hook, with that wire I needed to grab my bigger needle nose pliers because it was so stiff. At same time I ran wire for an electric stove using 6awg that was no more difficult to bend than the 12 gauge. Think it's just the brand, Cheaper brands are going to skip a step to meet a price.

J Tiers
03-04-2016, 04:17 PM
If you buy a decent quality outlet, you will find it has clamp plate connections. FAR FAR better. No need to make the "hook". With stranded wire, the "hook" often squashes out and lets strands stick out like a bad haircut, even if you tightly twist them.

Solid wire is a pain in the butt, and often in the hands as well.

Mcgyver
03-04-2016, 05:43 PM
I don't think stranded wire is allowed for electrical wiring, at least not for the usual 15-20 amp #14-#12 applications for standard switches and receptacles.

sorry, outside of a house its almost all stranded. You install conduit and pull the wires - they're stranded else they'd never pull. I did my entire workshop that way with 4 kinds power....yeah its a lot of conduit in place but its the safe way to go.

Mike Burch
03-04-2016, 05:59 PM
I bought some 2/0 & ir came steel wire copper clad for monster auto stereo systems. The idea is that most of the current runs on the outside of the wire? I'm not saying it's true just what I was told when I called about my purchase. It was of course stranded.
"Skin effect" does indeed exist. Any alternating current has a tendency to want to be denser towards the surface of the conductor, but the effect varies with frequency. It's a serious phenomenon at radio frequencies, where RF travels exclusively on the surface, but rather less so at mere audio frequencies.
"Copper-clad" was universal in the overhead telephone lines of my youth. Horrible stuff to work with. It's sometimes still used for wire antennas, as it stretches much less than pure copper.

PStechPaul
03-04-2016, 06:05 PM
I searched for stranded jacketed building wire, and found the following from Home Depot, but the stranded wire seems to be the ground on armored cable:
http://www.homedepot.com/p/Southwire-250-ft-12-2-Stranded-MCAP-Cable-55637701/202250338?AID=10368321&PID=994989&SID=C9165543USA-u2921221185-v242994&cm_mmc=CJ-_-994989-_-10368321&cj=true

The Southwire website shows that the current-carrying conductors are solid, at least up to #12 or #10:
http://www.southwire.com/commercial/MCAPandHCFMCAP.htm
http://www.southwire.com/documents/MCAP_BrochureNEW.pdf

Their NM-B standard Romex cables are solid conductors up to #10 and 7 strands for #8 and #6:
http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheetOEM122

I agree that for commercial work and pulling wire through conduit, stranded wire for #14-#10 may be more common, and the specification grade receptacles and switches likely have compression type terminals that work well with stranded wire. It may also be type THHN which has an additional covering of nylon insulation which makes it oil-resistant, tougher, and rated for higher temperature than the usual PVC.
http://www.southwire.com/products/oem-thhn-thwn-twn75-t90.htm

Blue Mule
03-04-2016, 07:00 PM
If you buy a decent quality outlet, you will find it has clamp plate connections. FAR FAR better. No need to make the "hook". With stranded wire, the "hook" often squashes out and lets strands stick out like a bad haircut, even if you tightly twist them.

Solid wire is a pain in the butt, and often in the hands as well.

Twist the strands CCW, then make the hook CW, and you'll see it all snug up neat and tight. If you have trouble making hooks, switch to lineman's pliers instead of needle-nose.

H380
03-04-2016, 07:33 PM
Also for bending solid into hooks for screw terminals a Klein electrician's screwdriver is great.

http://www.toolup.com/Klein-603-4B-2-Wire-Bending-Phillips-Screw-Driver

PStechPaul
03-04-2016, 08:09 PM
Here is a discussion of using stranded wire on screw terminals:
http://ths.gardenweb.com/discussions/2653471/termination-of-stranded-wire

The best method might be to use a crimp lug for stranded wire.

BTW, that discussion mentions stranded Romex being used for wiring of cabin cruisers. But it might have been for low voltage applications.

J Tiers
03-04-2016, 09:17 PM
Twist the strands CCW, then make the hook CW, and you'll see it all snug up neat and tight. ....

That works pretty well, but the clamp plate terminals are the real deal..... easier, works very well, likely more secure overall.

boslab
03-05-2016, 12:42 AM
Might be a bit time consuming but with stranded conductor you could tin the loop with a soldering iron after forming it, we used to do that with the stranded wire when terminating in small motors with screw down posts that had washers on when we ran out of lug crimps, I prefer the crimps but you have to work with what's available on times.
Mark

PStechPaul
03-05-2016, 02:17 AM
Soldering the stranded wire and then using compression fittings (including screw terminals) is not recommended because of cold flow, and subsequent loss of pressure and poor connection which can cause heating and failure.

vpt
03-05-2016, 08:04 AM
A quick zap of the tig on the end makes all the strands stick together. Works great for winch cables too so you don't prick up your hands.

Black_Moons
03-05-2016, 09:35 AM
Might be a bit time consuming but with stranded conductor you could tin the loop with a soldering iron after forming it, we used to do that with the stranded wire when terminating in small motors with screw down posts that had washers on when we ran out of lug crimps, I prefer the crimps but you have to work with what's available on times.
Mark

No this is a pretty bad idea IMO, because your wire will fatigue and snap right where the solder stops wicking into the copper, usally about 1/8" to 1/4" inside the insulation.

Solder joints MUST be 100% strain relieved to prevent this, usually by addition of a LOT of electrical tape. Not doable with a screw on connector.

J Tiers
03-05-2016, 09:39 AM
If you insist, there are crimp-on sleeves that include a strain relief, but they are not very good for screw connections, as they do not bend.

Black_Moons
03-05-2016, 10:04 AM
The skin depth at 60 Hz is about 3/8". That's a radius, so you wouldn't see much effect until you get up to around 3/4" bus bar. Speaker wire is sold in many "special" configurations, but the very best, if you can afford it, is white 18AWG zip cord.:cool:


I normally pick up a cheap 14awg extension cord when running speakers.

Exactly this. 'Good' (read as: best) speaker wire will be the lowest AWG, off the shelf copper wire you can buy.

You *might* be able to hear the difference on a long run of 18ga vs 14ga. You definitely won't hear the difference between $1/ft 14ga box store stranded copper extension cord and $200/ft silver plated, gold co(lo)red, oxygen free, litz, aerospace billet, space (in your wallet where your money used to be) rated audiophool 14ga wire.

And if for some reason your worried about skin effect. By all means spend the HUGE bucks and go with the $1.50/ft 12ga wire so its 'as good as' 14ga silver plated, litz yada yada yada yada wire.