Upgrade a Broken Extension Cord

My shop extension cord had popped the plug when I tried turning on my sander, pic 1. There was so much energy it took a chunk out of the prong, pic 2. So instead of throwing it away and buying a new one, I got some supplies and upgraded the worn outlet section, pic 3.

I bought:

Rounded gang box (rounded so it wouldn't snag as much when I move it around my shop)

And it's associated cover

15-Amp duplex outlet

Strain relief (that would fit the the gang box knock-out!!)

Tools I used:

Bolt cutters

Wire strippers

Razor knife

Screw drivers

Wrench

Here is a video of my entire process.

All of the following operations / modifications were performed with the extension cord disconnected from house power.

My plan was to NOT shock myself so be sure you are electrically safe when dealing with this project (or any electrical project for that matter)!

Another point to mention is that I knew the plug was the only bad component and would be easy to replace. This should go without saying but this would not help a dingy old frayed cord that you find in behind the water heater in the basement that has been there since 1974. Besides the actual plug, my cord itself was in good working order.

With the plug useless, pic 1, I cut off the head with my bolt cutters, pic 2 & 3. No big deal here.

Next, I bent the cord over to make it easier to remove the sleeve, as demonstrated in pic 1. Cutting into the orange sleeve without doing this may cause the razor to catch the green/white/black wires within. Putting tension on the sleeve by bending it over will make it easier for the razor to cut with minimal effort, pic 2.

Once that is off, pic 3, strip the wires back with your wire strippers (or the razor if need be), pic 4. Some outlets will have a guide for how much of the wire sleeve to strip, which is handy. Check the back of your outlet to see or any associated instructions that come in the package.

I took the bottom slug (the round piece of material in pic 1), pic 1, out of my gang box to feed the extension cord into later, pic 2.

How did I know it was the "bottom?" The bottom of the gang boxes usually have an indention for wiring grounding wire in series. In this case it doesn't truly matter but if you were wiring your house (hopefully not with extension cords) it is nice to know information.

I knocked it out with my screwdriver since it is made to be removed in the first place. It doesn't take a ton of effort with a pair of pliers or a wrench. I just move it back and forth like a coke tab. Feed the extension cord wire in through the bottom hole and up to the strain relief. Allow enough cord to be inserted into the gang box for wiring up and screw on the locking nut to the strain relief, pic 3.

Why use a strain relief? As the name implies, it relieves strain from the cord which is especially nice for the shop or a job. Think about your phone charger cord. If you repeatedly remove it from your phone by pulling the cord and not the plug itself (I can admit I do that all the time, too), what happens? The sleeve gets separated from the plug and gets mangled and eventually you have to jiggle the wire just right for it to actually charge. Kind of like tuning your old tv with the rabbit ears.....what do you mean no one gets that reference?!

Anyway, strain relief can relieve strain from your plug and it is relatively cheap to increase the longevity of your extension cord.

Depending on the outlet, there may be a hole to insert the wire as opposed to doing a shepherd's hook around the associated screw. Be sure you verify the proper orientation prior to wiring up the outlet. And remember:

Silver = White = Neutral

Gold = Black = Hot

Green = Green = Ground

I did my shepherd's hook and screwed the screw on tight but not torqued either. Also, ensure your hook will loop and pull it tighter and not loosen when you tighten the screw, i.e. hook to the right and not the left, if you can visualize that.

Once the wires are in place, I took off the unnecessary mounting straps, pic 3. These are the "ears" above the retaining screw that may interfere with screwing on the cover plate. I screwed the retaining screws into the gang box, pic 4, followed by the cover plate itself, pic 5.

Afterwards, I plugged the extension cord in to my house main power, and checked the gang box for any shorts just to make sure there were no stray wires touching the box. I then checked the outlet itself, pic 6, to ensure it has 120V power. It did

Now it is ready for use. Hooray, another project saving stuff from the scrap heap!

I hope this helps someone in a similar predicament and if there are improvements or electrical concepts I completed missed the mark on, let me know in the comments.