480 Volt 3 phase extension cords

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Dave B56

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Hi Everyone
At my place of employment which is a steel fabricating shop we have a reoccurring problem of the extension cords coiling up.
The cords vary in length from 25' to 50' and are made of #6AWG 4wire soow. The welders from what I see in the wiring chart draw 15 AMPS on 480 volts.
I'm posting some pics of them to see if anyone has an idea what the cause is. I usually cut them up before they get as bad as this one.
I can't find anything on the net. so I thought with all the knowledge here some one would have an idea.

THANK YOU
 

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GoldDigger

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Not just as simple as the users always turning in the same direction as they use the cord?

Does the cord get wound up and unwound in the course of use? If so the cause could be winding the coil from one end all the time and then just pulling it straight out when uncoiling it again. Happens that way to garden hoses too.

The twist in the conductors inside the outer sheath can potentially tend to untwist if the initial twist is very tight. That would have a tendency to put an opposite curl into the overall cable.
 

Jraef

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I'd venture they are coiling them up like a rope on the floor or a hank from elbow to hand, then pulling them out straight from the middle for use later. You see the same effect by doing that with a box of Romex; punch a hole in the center of the box with your fist and start pulling it out from the middle, it will look a lot like that.

Get some cable reels, that's what they are for.
 

jumper

Senior Member
I'd venture they are coiling them up like a rope on the floor or a hank from elbow to hand, then pulling them out straight from the middle for use later. You see the same effect by doing that with a box of Romex; punch a hole in the center of the box with your fist and start pulling it out from the middle, it will look a lot like that.

Get some cable reels, that's what they are for.

Interesting. I would see guys with cords in similar shape to the OPs and never could figure how the cords could get so distorted.
 

GoldDigger

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Ah yes, not uncoiling cord before putting a high current through it?
I love the consumer oriented spring cord reels and cord minders that tell you to make sure to uncoil the cord completely before using it.
The only way to avoid that (mostly) is to use a cord minder that only accepts a single layer of cord in a spread out flat coil.
 
Interesting. I would see guys with cords in similar shape to the OPs and never could figure how the cords could get so distorted.

It's forcing the cable into a coil it doesn't want to follow (although I'd like to watch someone try coiling a 6/4 SO around their arm:D) and probably also pulling from the middle. For that size, unless you use a reel, either over/under (AKA 'flip') coil or lay in a figure-8 pattern.

There's a nice description of flip coiling at http://techno-fandom.org/~hobbit/flipcoil/howto.html.
 

GoldDigger

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It's forcing the cable into a coil it doesn't want to follow (although I'd like to watch someone try coiling a 6/4 SO around their arm:D) and probably also pulling from the middle. For that size, unless you use a reel, either over/under (AKA 'flip') coil or lay in a figure-8 pattern.

There's a nice description of flip coiling at http://techno-fandom.org/~hobbit/flipcoil/howto.html.
Before I learned how to do this (from a stage tech) the best I could do was a figure 8 wrap around hand and elbow. It worked for small diameter cords, as long as I did not wrap too tight. If I pulled too hard it was almost impossible to get my hand and forearm out of the finished figure 8.

Another technique that is very easy for anyone to learn is the "doubling" method.
Start with the cord lying untwisted on the floor. Pick up two ends and bring them together (like folding a sheet.) While holding the two ends work your free hand down to the far end of the U.
When you get there, transfer the U to the hand with the two ends and repeat the doubling process.
Continue until your bundle is between 2 and 4 feet long (depending on diameter of the cord and the bundle.)
Now either put a velcro cable tie around it or tie the whole bundle loosely into a single overhand knot.
It is not as foolproof to unwind again as the flip coil, but it is a lot faster and easier to learn. And it works for both round and flat cord.
The flip coil is harder to manage with flat cross section cord, although you can get used to it.
 

SceneryDriver

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Before I learned how to do this (from a stage tech) the best I could do was a figure 8 wrap around hand and elbow. It worked for small diameter cords, as long as I did not wrap too tight. If I pulled too hard it was almost impossible to get my hand and forearm out of the finished figure 8.

It's us theater-folk to the rescue again! :D Cables must be coiled over-under or this will happen. I've seen extension cords that look terrible after just a few weeks of use because someone wasn't coiling them properly.

http://www.youtube.com/watch?v=1Qngim6zuAM

You'll know you've coiled it correctly if the coil doesn't want to twist into a figure-8 when you let it go. The underlying idea is to coil the cable without imparting a twist with each wrap.

If your cables are too heavy, a cable reel is a very good idea.


SceneryDriver
 
It's us theater-folk to the rescue again! :D

He he, ya. I learned flip-coiling from a broadcast guy maybe 40 years ago. Funny that AFAICT all broadcast people do flip-coil, and theater people towards the West coast do but it's rare on the East coast. Don't know about the film industry, but I heard they used to designate power leads by the number of tie lines and how many knots in them at each end; EGC was something like two strings with two knots in each. I'll stick with colors, thanks.

REAL men can hank a 6/4 SO cord...:happyyes:

How about a 4/0 SC cable:lol:? We all get our entertainment somehow.....
 
I'd venture they are coiling them up like a rope on the floor or a hank from elbow to hand, then pulling them out straight from the middle for use later. You see the same effect by doing that with a box of Romex; punch a hole in the center of the box with your fist and start pulling it out from the middle, it will look a lot like that.

Get some cable reels, that's what they are for.
Exactly my thoughts
 

Aleman

Senior Member
Location
Southern Ca, USA
I have seen 1 cable like this on a pump cart, cable is 12-4 SOOW. We have a bunch of carts but only this one has the permanent wind on it.
I'll have to look at it but the wind will be from how it is wound up when out of use. I believe it is twisting that causes this effect. Also had a small
electric hoist that the operators would wind the same direction and the cord ended up looking like the OP's.
 

SceneryDriver

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NJ
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Electrical and Automation Designer
He he, ya. I learned flip-coiling from a broadcast guy maybe 40 years ago. Funny that AFAICT all broadcast people do flip-coil, and theater people towards the West coast do but it's rare on the East coast. Don't know about the film industry, but I heard they used to designate power leads by the number of tie lines and how many knots in them at each end; EGC was something like two strings with two knots in each. I'll stick with colors, thanks.



How about a 4/0 SC cable:lol:? We all get our entertainment somehow.....

Yeah, I've seen some pretty hinky stuff when it comes to proper color code on Cam-Lok feeder. Some tours and roadhouses are really good. Some... not so much. I think the older guys didn't care about color on Cams so much, as you used to be able to only buy black connectors; colored tape if you were lucky. All the other colors are comparatively newer.

I'll leave the grunts to hump 4/O Cam feeder from the company switches to dimmer beach :D That much copper is heavy!


SceneryDriver
 

kwired

Electron manager
Location
NE Nebraska
I'd venture they are coiling them up like a rope on the floor or a hank from elbow to hand, then pulling them out straight from the middle for use later. You see the same effect by doing that with a box of Romex; punch a hole in the center of the box with your fist and start pulling it out from the middle, it will look a lot like that.

Get some cable reels, that's what they are for.
It's been a while since you run any NM cable hasn't it?:) It hasn't been packaged in a box for at least 15 to 20 years AFAIK, shorter lengths are just wrapped in plastic anymore.
 

Jraef

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It's been a while since you run any NM cable hasn't it?:) It hasn't been packaged in a box for at least 15 to 20 years AFAIK, shorter lengths are just wrapped in plastic anymore.
Yep, it has been a while. I guess I knew that now that you mention it, because it was already in plastic wrap on the stuff I used on my house 10+ years ago. It's just that my first thought went back to my apprentice days, busting boxes with my fist, grabbing the end out of the center and running to where the J-man told me to go with it...

Thinking back on it now, they were likely doing that just to watch me jump for them.:slaphead:
 
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Dave B56

Member
Location
United States
THANKS everyone now that I know the problem I have to find the cure trying to get a welder to do something different from what they've always done can be next to impossible.

Thanks again everyone
 
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