Solid copper wire

[robh 12]

We have alot of solid copper wire in our plant. Alot of the control wires are #14 awg solid. Most of this stuff is real real old. Any time I can I replace it with stranded. I have been told by some of the "old timers" (no offense to any one who might be considered an old timer) that thats all they ever had to use. Why is that, and when did stranded become a better choice in a lot of applications?

[TimWilborne 108]

I've always heard stranded holds up to vibration and obviously movement better but I just left a 40 year old plant that was full of solid wire. No real problems with it so I'm not sure

[robh 12]

Yeah we don't have alot of problems with it. The insulation is kind of a pain in the butt whenyou have to strip it. Stranded is definatly more flexible and easier to work with. Just wondering why solid wire was the top choice when they installed it in our plant.

[TimWilborne 108]

Would it have been easier to work with if you didn't have fish tapes and all of the new gadgets? I pretty much reaching here but have always been curious also. This plant was put together completely with manual labor. The cranes were put on with block and tackles. Could solid wire have been significantly cheaper back then?

[robh 12]

I bet cost probably had something to do with it. I had never thought about the fish tape theory. But if cost was the big issue, I wonder what the technological breakthrough in wire production was?

[TimWilborne 108]

Solid wire would be simple. Just drawing wire and molding insulation around it. Stranded wire would be a bit more complex since you would have to draw the individual wires, then put them together, then mold. One extra step? I have never seen electrical wire drawn. I have seen steel wire drawn and I have seen quill rooms of wire that is fed through extruders in the tire industry. Don't know if that is similar or not.

[TimWilborne 108]

Well I have been Googling and it should be a simple search to see how each is manufactured but I think I'm going to have to get Mickey or PDL in here to find a link

[Mickey 71]

More stuff found on web, still looking for how its made. "Stranded vs. Solid Wire This one is a bit of a mind-boggler, but it's important. When electricity flows through a wire, it mostly flows on the surface of the wire, not through the middle. This means that a "wire" of a given size that made up of many smaller strands can carry more power than a solid wire - simply because the stranded wire has more surface area. This is why battery cables in your car and welding cables are made up of many very fine strands of smaller wire - it allows them to safely carry more power with less of that power being dissipated as heat. When looking at a chart or description of wire capacity, take note of whether it is referring to stranded or solid wire - some charts may not specify but instead assume a default based on the typical wiring used in a given application. For example, almost all automotive wiring is stranded while almost all home wiring is solid." http://www.picwire.com/technical/paper9.html http://www.barbwiremuseum.com/makingwire.htm http://en.wikipedia.org/wiki/Stranded_wire Edited 3 Nov 2006 by Mickey

[TimWilborne 108]

Thanks Mickey. Great information. I'll get this Googling down one day Thanks TW www.twcontrols.com

[robh 12]

Great awnser Mickey. I guess I should have remembered some of that stuff from school!

[Mickey 71]

Don't thank me ,thank Mr. Google.

[run4suds 3]

It's called 'Skin Effect' I learned about in Electronics training in the Corps. The skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. That is, the electric current tends to flow at the "skin" of the conductor.

[panic mode 246]

that's correct but... for skin effect to happen, one needs high frequencies, not DC or AC with only 50 or 60Hz. effective surface area increase due to stradning is very small and has relatively little effect since cross section is still round. PCB traces on the other hand are very flat and that is significant area vs cross section ratio. Battery cable in a car is flexible for only two reasons: easy of installation and properly addressing vibration issue during life of the vechicle. Most homes don't have wheels and don't move, this is why solid wiring is used.

[gravitar 3]

The way I've seen OLD panels designed, solid wire would be a lot more convenient. Back before wireduct was thought of, panelbuilders would just leave bundles of wire out in the open and baled together with string or folded-over aluminum tabs. In a well-laid-out panel, each wire would be bent on 90 degree angles from connection to connection, much like plumbing. The end result would be a panel that is as beautiful to look at it would be a pleasure to work on. You simply wouldn't be able to do that with stranded wire. Even if you were to bend it on right angles, it wouldn't support its own weight. It would partially return to its original form and just end up looking like a mess. Solid wire is much easier to wrap around screw terminals, too! I'll have to take a picture of the next panel I see that was done "old school". Its kind of a shame this is a lost art!

[larry818 0]

Kind of a late answer, but oh well, It needed to be a lost art. At one time this was really common, but what these electricians didn't know was that wire has a minimum bend radius, about 8x the diameter. These guys would bend wires at a sharp 90 degrees with pliers, typically breaking the solid core about half way through. If there was any vibration nearby, the wire could and would break all the way through. I worked with panels feeding heaters sometimes in the hundres of amps and have seen more than a few wires burned at the bend. I used to wire with waxed string (not that wire duct wasn't available, but it was considered radically expensive in the '70s) and I always bent my wires around a copper pipe for radius. Sometimes I miss the waxed string bundles. There was an art to getting the panel finished with all the wires never crossing in the bundles.

[robh 12]

I wish we knew how Tesla said electricity could be transmitted without wires! Might screw up our wireless internet though.

[BudMan 1]

Larry, Just because you miss the waxed string bundles. The photos are not of an industrial panel but of a Electro-Mechanical pinball machine that used waxed string bundles. The wires are color coded (no wire tags) and used the fabric style coating. http://i237.photobucket.com/albums/ff189/H...sticBackbox.jpg http://i237.photobucket.com/albums/ff189/H...icPlayfield.jpg http://i237.photobucket.com/albums/ff189/H...ntasticTilt.jpg Gravitar, Bring back any good/bad memories?

[panic mode 246]

aaach pinball machines...!!! i used to repair those and it was a good money plus lots of fun...

[larry818 0]

Funny, when I fixed them it was always for friends, was for free, and was a nightmare...

[panic mode 246]

i was doing it as a teenager, making VERY nice income - i could do in few hours what my parents had to work for a month. rules of supply and demand... 99% was dead simple fix, only few times i had to dig deeper and change CPUs or EEPROMs...my favourite was Bally... very easy to find material and simplest to maintain. convenient jumpers and inverted signals on CPU boards (specially handy when changing EEPROMs since 25xx ware goners and it was time of 27xx - almost the same pinout but not straight replacement ). there was bunch of guys who wanted easy money but they had no clue about basics. one of them was changing transistors until driver board PCB traces started peeling off. problem was that diode accross kicker coil was toast - one kick and another transistor gone... man, i miss those days... girls everywhere...and i was the king... i better finish this post before my wife sees it and kills me...

[Sleepy Wombat 27]

lol..... Brought a DE Star Wars recently and have had a fun time repairing etc to get it working again (once i managed to get my hands on a schematic... cleaned of around 15 years of smokey dust off the play field and came up a treat... I am still the king...

[BudMan 1]

I started working in the coin op in the mid 70's and now still do it on the side. You are right I thought I was King s**t back then (money, good job, girls and all with little education just a background in electronics). Working at a distributor, going to coin op shows and working on the road (bowling alleys, Bars, Game Rooms and every little store that had room to put a game or two in). I think I was a smart RAT because in the late 80's I jumped ship. I had seen a lot of operators dumping their routes, game rooms closing and the influx of the home version games. It is still in my blood. I loved the old EM's because all you needed is to understand relay ladder logic and have a jumper wire, a points (relay contact) bender and maybe a burnishing tool. Funny story, Space Invaders video game at a greasy spoon. Has game sounds no video. Normaly it is a bad monitor or no video output from game board. Opened game CRT was glowing, had High Voltage maybe it just needed the brightness turned up?? No just had to scrape the years of grease and dirt off the front of the monitor and reflecting mirror. Problem fixed!! Bud Edited 29 Nov 2007 by BudMan