Introduction: Create Electrical Adapters/Extension Cords

Experienced makers can read bold passages!

I enjoy a variety of projects and all of them require power. Not all power outlets were created equal. Using wire for a higher amperage or voltage than it was rated for will likely lead to fire, electrocution, and possibly death. For this case, we are using a simple extender rated for 50 amps. The two ends will plug into each other and I have gathered different plugs, also rated for 50 amps to add to this wire. This is straight forward.


Adaptability. It will work as originally designed.* It will work as an extender for the new type of connectors. And, it will work separately as 2 different types of adapters.

If you don't know how power works, take a look at the video.

I recently took delivery of an electrical car and wanted to be able to charge it wherever I go, as I work at a different site almost every day. The standard outlets we have in our homes are usually limited to 15 amps which will get me roughly 3 miles/hour of charge. This is worthless, so I needed a way to connect my higher amperage charger but there are so many options at this level. My charger came with the NEMA 14-50 connector which is common in RVs (caravans) and supports up to 50 amps 120/240v. The goal is to come up with adapters for plugs of this level. This is the first adapter.


Price will vary based on the wire. The better the rating, the more it costs. You might be able to extend a lamp for less than $20 but this project cost me near $150
  1. Extension cord of gauge X (in this case: NEMA 14-50, 25ft of 6 awg - 4 conductor - 300v outdoor flexible cable) Amazon $100
  2. male and female connectors equal to rating X Amazon $35
  3. screwdriver (+ & -)
  4. sharp knife or blade to cut the wire jacket back

Step 1: Acquire Wire and Connectors

I picked up these connectors which are also rated at 50 amps so I will be able to use this extension cable either way or as a converter. What I mean is that I have an extension cable of connection type 1. (not shown yet)

I bought a connector type 2. So the cable 1------1 will become 1---22---1.

Because they are equally rated, I can connect them backward by flipping the sides. It will look like 2---11---2. Understand?

If connector 2 was rated less, I would not be able to connect them back because this could allow a higher amperage to pass through the inferior connector 2 leading to meltdown, fire, electrocution, hurty death, etc. Big NO-NO.

Pro-discussion: I picked up the left connector from Amazon, but the right from a surplus store. While the pinout is the same, the right connector is rated for 480v and thus had different guide pins on the outside of the connector that I had to remove. This is what happens when you are cheap.

Step 2: Cut Wire

Find a good place to cut the wire. If you don't put it in the middle, make sure that you don't put it so close to one end, you do not have enough room to splice the connector.

If you are using a wire without ends, just attach your connector to the ends.

I placed my connector near the male end. Think about this. The female end is what will always be connected to my charger. So, when using this wire as an adapter (one of 2 parts) I will still have considerable length.

When you peel back the housing, be careful not to cut into the insulation of the individual wires inside. Doinso so will compromise the integrity of the wire and cause electrocution, sparking and more deathy things.

Once you cut it, do not forget to slide the connector housing over the wire before you start stripping the wires. (Read that line again)

  1. Cut wire
  2. Slide connector housing over each end (gets me every time)
  3. Cut back ~1.5 inch of the wire jacket from each side
  4. Strip ~3/4 inch of each conductor's jacket

If the place where the wires all go in is not equal, the connector might come with a paper telling you how long to cut each wire with respect to each other.

Step 3: Line Them Up

If done correctly, the conductors inside the cable should match up without having to twist wires over each other.

If you are using a new wire without connectors and they don't line up, try the other side of the wire and see if that works better for you.

Make sure you do not create a male to male adapter. no Bueno.

In a 4 conductor wire, they will typically be colored red, black, white, and green. Red and black (sometimes blue) are "hot" lines connecting the power. Those are deadly when live. The negative (white) is also deadly when live if there is any current going through it. The ground is green. Thats easy.

Step 4: Insert and Tighten

Insert the bare ends into the channel and tighten. The wire should not be bare outside of their little ports. Cut the wire back if they are. once done, make sure you clamp the wire ends so that a hard pull does not accidentally pull the wires out. That could be deadly too.

Plug and test for correct pinouts as I have seen cheap overseas plugs incorrectly labeled. Happy electricitng!