My partner used to have the bad habit of pulling electric cords by the cord rather than the plug. Now he pulls the textured tubular part in between the cord and the plug. Is this safe? Can it still damage the device?
When you pull on the cord you are putting tension on the jacket, and cable jackets typically can’t take much tension. In addition he may also be inadvertently pulling on the wires contained within the cord, thereby putting stress on the electrical connection inside the plug. I’m not saying it will immediately fail when he does this, but it’s possible it could eventually fail due to cumulative effects if it’s done over and over.
You mean the strain relief? Same as above, though a strain relief is designed to take more tension.
Why is he not pulling on the plug??
This almost looked like something I would have posted. If you are speaking of that ridged section between the cord and the actual plug head, yes. I looked this up before. It’s used for the cord to be able to safely flex and bend (within reason) without causing damage. I’ve been doing that for years to be on the safe side.
… and welcome to the SDMB … pinkorangebeige … love your username …
I have a vague feeling that the “never pull a plug out by its cord” rule was invented in a time of much more cheaply-made and lower-quality cords than is standard today. Like those cords that were covered in fabric instead of rubber.
I still pull by the plug because the habit was drilled into me by a thousand electrical safety lectures, but I can’t really imagine significant damage being done to a modern plug by pulling on the cord.
Pull the cord enough times and something will break. With good quality cords that will be a lot of times. Cheap zip wire cords are pretty flimsy and could break from a sharp tug. They’re usually attached to a cheap plug with minimal strain relief and the plastic could crack and expose wire which is a shock and fire hazard. Just be careful and check for damage on the cord near the plug.
Your biggest danger is fatiguing the copper conductor. Then you can end up with a break that becomes a fire hazard. OTOH, the only cords I have ever seen that have become that bad were the subject of external trauma. Tugging on the strain relief is unlikely to be a significant issue.
I also need to know how tight the plug receptacle is. Some of them are pretty loose.
If you mean you’ve been pulling on the strain relief for years, you’ve actually been doing it the unsafe way for years.
By trying to keep your fingers an unnecessary distance away from the metal prongs you’ve been incrementally damaging every cord you’ve ever unplugged.
With modern equipment you’ve probably never done enough incremental damage to actually matter. But you have been slowly eroding the built-in safety margins.
Which goes back to my point in the other thread that something about your overall attitude and approach to electricity is far enough off-kilter that IMO you really shouldn’t be doing DIY electrical stuff.
Once upon a time, back in Ye Olde Stone Age, the cord was individual rubber coated wires
in a cloth sheath, which was poked through the end of a big rubber coated plug, and the wires themselves were screwed to terminals.
Pulling the cord actually pulled the wires tight on the terminals, after a while the wire fatigued and began to break.
Then things got interesting and sometimes fire ensued.
With the materials and molded design used now days, you probably wont break the wire, but still a bad idea.
If you pull it off center, you may not do the wall receptacle any favors, and if it is the kind that mounts to the drywall itself and not a stud, you may just rip it from the wall.
[QUOTE=Weisshund
If you pull it off center, you may not do the wall receptacle any favors, and if it is the kind that mounts to the drywall itself and not a stud, you may just rip it from the wall.[/QUOTE]
People do that? Seriously? I have never ever seen that. How do people get away with this stuff building houses?
I’ve done that when I’ve added an outlet long after the wall was built. Drill a hole and run the wire up from the basement . Cut out the hole for the outlet. Hopefully the wire is close so it can be found easily. Certain outlet boxes are built for just such a purpose.
“Old Work” boxes.
Yanking an AC/DC plug (wall wart, adapter, transformer cube, etc.) out by its cord once will likely kill it. Once upon a time, our science department bought a dozen of the variable voltage types to use teaching simple circuits. After one semester, exactly none of them worked- not because of yanking the cords, but by OCD types winding the cords neatly (and too tightly) around them for storage. This habit broke all the tiny wires inside the thin cable, right where the cord met the strain relief.
“strain relief” portion? Can someone cite/post a pic?
Here: https://cdn.sparkfun.com/assets/c/a/3/6/6/5113dc95ce395fe501000000.png The strain relief begins where the arrow points is and is the tapering portion extending to the right.
It ensures you don’t kink the wire right where it enters the rigid part of the connector. If also transfers any pull force from the main length of cable into the body of the connector without letting the interior wires get stretched.
Here are a bunch of other examples but for 110v power cords, not audio.
https://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&q=strain+relief+power+cord
Long after the wall was built is totally understandable. I was thinking more like new construction.
Those are called “old work boxes” or “remodeling boxes”. They aren’t for new construction. New work boxes are typically nailed to a stud or attached to a bar hanger which is attached to studs.
Just looked them up, I could probably find some good use for these in the future… I had no idea. Probably would work best with some toggle bolts to anchor. Thanks!
There’s no way to use them with a toggle bolt, and the boxes have built-in rotating “ears” to anchor them to the drywall. They are perfectly secure if not abused.