Desktop Power and USB Outlet (120v)

I was inspired by commercial products that I had seen online that provided a USB and 120v Power Outlet with an extension cord. My issue with the commercial products I had seen was either cost or lack of features. I wanted something more economical that wasn't $100 USD or more but I also wanted the features of smart power that would adjust USB provided power to meet the needs of the device(s) plugged in.

This is the results of my research and experimentation.

The only thing I didn't experiment with was paint. The boxes already came painted and instead of painting the face plates, I chose to purchase face plates that were metal and already colored. If I was to make a lot of these, purchasing a metal faceplate and painting them would be more cost effective than buying some of the colored face plates.

Supplies

• 1 Gang Electrical Box - Sigma White Electrical 14250 box
• Note, this box includes plugs for the holes I am not using
• Wall Outlet with USB - Leviton T5633-W
• Standard 1 Gang Device Faceplate - ENERLITES Decorator Switch Metal Wall Plate, Stainless Steel Outlet Cover, Gloss White
• 1/2" NPT Cord Grip Strain Relief - BR13NA Dome Connector (.023 - .47")
• 3 Prong Power Cord - Violet 15' 3 Prong Cloth Covered Power Cord (Round) from Color Cord
• Lever Nut - Wago 221-413
• Ground Wire
• Electrical Tape
• Self Adhesive Rubber Bumpers / Rubber Stoppers (not pictured)

Tools

• Scissors
• Wire Strippers / Wire Cutter
• Wrench or Adjustable Wrench
• Phillips Head Screw Driver
• Flat Head Screw Driver

Optional Tools

• Outlet Tester
• Tweezers

Supply Choices

Outlets

There are a variety of outlets in the market that provide your traditional electrical plug with a ground and also add a USB Type A plug (the rectangular one). More recently there have been outlets that have added a USB type C plug as well or even dual USB USB type C plugs. When considering your outlet choices, criteria that I recommend include price, watt delivery per port, how many amps the outlet supports, and do you want / need smart power delivery.

For my projects, I have chosen to use the Leviton brand outlets. I have used both the T5633 and the T5635 outlets in my project. The specific Leviton outlets I use have smart power delivery which throttle down the power delivered when the device doesn't need it (assuming the device supports that functionality). A single USB port on the T5635 can provide 30 watts of power if 1 device is plugged in or 15 watts of power per device when 2 devices are plugged in.

Electrical Cord

For a project like this, which is going to be visible and sit on a desk or some other place that is visible, I wanted a cable that isn't just black plastic. I like the look of cloth covered cables and there are multiple sites out there that have a variety of options to choose from. One of the major drawbacks of cloth covered cables is that you won't see inner cable wear as it is covered by the cloth and if the cloth gets damaged, it can be unsightly. As I am not planning on moving the cable frequently, the inner cable shouldn't be moving and bending enough to create this wear so I am not concerned about these drawbacks.

Also, make sure that you are using at least 14awg to avoid risk of fire.

Cord Grip Strain Relief

I wanted to find a way to both protect the cable from the metal edges of the hole as well as to prevent the cable from being pulled out of the hole or pulling against the outlet. The phrase I stumbled up was cord grip strain relief. There are a couple of things you need to know when you are searching for this product. What is the size / thread of the hole in the electrical box? My box is sized 1/2" NPT for all 3 holes but there are boxes in 3/4" as well. What is the shape of the cord? Generally this is round but it could also be flat. What is the diameter (width) of your cable? I used a caliper to measured my cable several times and got an average of .245" diameter. When you are buying the power cable, it maybe listed there as well.

There are a variety of cord grip strain reliefs on the market. Since my cabled measured .245", I needed the internal dimensions to get down to .24" or smaller when tightened to provide the strain relief. I originally found some "white" ones on amazon that were plastic. While they worked for my initial test, I was unhappy that they weren't actually white but more gray which didn't go with the colors I was looking for. I managed to find some nickle plated brass ones as well as some black metal ones that, while a little more than I wanted to spend, looked great.

Additional Supply Thoughts

For the electrical box, I went to a couple of my local hardware stores to see the options available. I wanted a metal box in case I wanted to paint it and I also wanted to make sure that there was a ground screw so that I could ground the outlet box as well. I am very happy with the quality the box and the paint on the box so I used the stock box.

For face plates, I went online and found different colored face plates that were metal. Similar to the electrical box, I wanted to have the option to paint it. I also went with metal as I feel it will hold up better in case the box gets hit or kicked around.

Since I have a ground screw from the electrical box, and a ground screw on the outlet, I needed a wire connector. I am not a fan of the screw type wire connectors as I like a more secure connection. I chose the wago lever nut for a positive wire connector.

Task - Remove the outer sheathing to expose the required length of inner cables

Result - 3" exposed of inner cables from power cable

Some of the cables I purchased already had about 1 1/2" of outer sheathing but I needed to remove close to 3" for my purposes. Other cables I purchased did not have the outer sheathing removed. This probably the hardest part of the entire process as the outer sheath must be removed WITHOUT cutting the cable insulation for the inner cables.

There are really nice cable strippers that would remove just the outer sheathing but I do not own them. Instead, I have wire strippers with very sharp cutting edges. I could have also used a razor to do the initial cutting.

1. To prevent fraying of the cloth cable covering, I apply some electrical tape all the way around.
2. To start, I use the cutting edge to cut a completely around the cable. After making the initial cut, I bend the cable to see if I can see any of the inner cable insulation. If I do not, I cut a little more until I can see the inner cables. If you are not careful, you may cut the inner cable. If you see the copper from the inner cables, you need to cut everything off and start over. The first time I ended up cutting almost 9" inches off from having to start over so many times.
3. Once you have all 3 inner cables visible, you need to cut the remaining portions of the outer sheathing. I used tweezers to do this but you could use almost anything as long as you don't cut the inner cable.
4. Once the outer sheathing no longer connected, you can completely remove and discard.

Task - Ground wires cut to length and the cable insulation on all required wires

Results - Wires prepped for installation

• Black / Hot wire (Power Cable) going to outlet (back wire length) (1/2")
• White / Neutral Wire (Power Cable) going to outlet (back wire length) (1/2")
• Ground Wire (Power Cable) going to wago (wago length) (7/16")
• 6" Ground Cable - 1 end outlet ground (side wire length) (3/4") and 1 end in wago (wago length) (7/16")
• 3 3/4" Ground Cable - 1 end electrical box (side wire length) (3/4") and 1 end in wago (wago length) (7/16")

The first picture shows my sample wiring guide I used for test fitting everything together. The lengths of you cables may vary depending on what type of box you use, how you orient the box to the outlet, how you are fastening cables to the outlet, etc. I recommend, if you can spare some materials, to do a test fit before screwing everything tight.

Prior to assembly, I prep all of the wires by cutting the ground wires to length and then stripping off of the cable insulation around each of the cables. From my testing, I needed one ground cable 6" in length that would go from the wago nut to the ground on the outlet. I need a second ground cable 3 3/4" in length that would go from the wago nut to the ground screw on the electrical box. Cut the two ground cables from the spool of ground wire.

To determine the proper length to strip the cable insulation, read the directions for the different items that were purchased as they usually have written or visual guides. For the power outlet, there are two different size guides. (Terminology may vary between manufactures.)

On the back, the right rectangle says back wire. Back wire is for going between plates or in specially designed holes for inserting cables. I don't recommend using the holes as it provides minimal contact with the wires and hinders any repairs needed to make. If it is going between a plate, like in this example, I think it is a great choice.

On the back, the left rectangle says side wire. Side wire is for usually coming in from the side and wrapping around the screw.

1. For the black / hot and white / neutral wires I am stripping to length per the back wire length. I am using the 16 gauge wire stripper slot to make the initial cut and then moving to the 14 gauge stripper to remove the cable insulation.
2. For the ground wire on the power cable, I am using the stripping guide on the wago nut and following the same steps as I did for the hot and neutral wires.
3. For the 6" ground cable, I am using the stripping guide on the wago nut for one end and using the side wire guide for the other end as this wire will wrap around ground screw.
4. For the 3 3/4" ground cable, I am using the stripping guide on the wago nut for one end. The other end is going to go around the screw in the electrical box which did not come with a cable length guide. I am using the side wire guide as my estimate and it seems to work fine.

Note - Some pictures you will see the wire stripped before the putting the power cable through the cable guard and housing. This is due to the fact that I usually stripped the cables after they were in the housing. I took some pictures for ease of demonstration with this done prior to that step.

Task - Install hole plugs and cable strain relief

Results - all holes plugged or prepped for cable installation

Orientation of the box is important at this point. Note the position of the ground screw in the box. I specifically chose to put the ground screw at the opposite end from where the power cable will enter the box, this is to prevent a bunch of cables being routed where the cable is also entering the box causing space issues.

Prior to installing the outlet, I need to install the cable wire guard and plugs for the unused holes. The box I purchased came with color matching plastic hole plugs. If the box does not have them, they can be purchased separately.

1. I start with the back of the electrical box and use my fingers to insert the plug and start tightening, I use a Flathead screw driver to tight the rest of the way being careful not to over tighten the plug.
2. I move to the top of the electrical box and use my fingers to insert the plug and start tightening, I use a Flathead screw driver to tight the rest of the way being careful not to over tighten the plug.
3. At the bottom of the electrical box, I insert the cable strain relief and I tighten using my fingers as much as possible. Note that there are two different places use a wrench. The one closest to the electrical box is for tightening the cable strain relief to the box and the other is for tightening the gasket around the power cord. I use a wrench to finish tightening the cable strain relief to the electrical box. I have covered the wrench with tape to prevent damage to the electrical box as I tighten.

Task - Thread cable into electrical box and attach hot and neutral wires to the outlet.

Results - Outlet connected with hot and neutral wires.

Connecting the Hot and Neutral wires to the outlet is fairly straight forward. Most outlets mark which post is for hot and which is for Neutral. In this case (second picture) the back of the outlet lists Hot and White.

1. Insert the power cable through the cable strain relief and into the electrical box. Do not tighten the cable strain relief yet. If you have not already done so, strip cable insulation off of the wires. I usually pull extra cable through to make it easier attaching the wire to the connectors and wait until the end to tighten the cable strain relief.
2. Orient the outlet to the way you will install the outlet into the electrical box, this will reduce wire twisting and strain as you assemble everything together.
3. Insert your first cable into the appropriate position and screw tight. I found it easier to work from right to left due to how the cables lay and being right handed. You could do this from left to right as well. For this outlet, there is a plate under the screw and I am trying to make sure that I am getting the wire between the side of the outlet and the metal plate. I am also trying to verify there is no copper outside of the plate area that can make contact with any other wire before screwing tight.
4. Repeat the process for the second wire.

Task - Connect all ground wires

Results - Outlet has all wires connected and electrical box has ground wire connected to power cable

1. Prior to assembly, lift all of the wago levers so they are perpendicular to the box.
2. Insert the ground cable into the wago nut and lower only that lever down to secure the cable. I chose to use the middle position for the ground wire in the power cable but you can use any of the holes in the wago nut.
3. Insert the 3 3/4" ground cable into the wago nut and lower the lever for the cable.
4. On the available end of the 3 3/4" ground cable, make a J shape with the copper.
5. Hook the copper end around the ground screw in the electrical box and then screw tight. Pull on the ground cable that is attached to the electrical box to validate that it is secure.
6. Make a J shape with the 6" ground cable and hook that around the ground screw on the outlet. Screw tight and validate that it is secure.
7. Place the second end of the 6" end of the ground cable into the wago nut and lower the lever.

Task - Insert outlet, test outlet, and tighten cable strain relief

Results - Working outlet ready for final steps

At this point the outlet is now ready to be tested. I like to place the outlet into the box prior to testing so that there are no exposed points where electricity can be distributed. As you go through the process of placing the outlet and tightening screws, don't force anything. There are several ground wires as well as the main power cable under the electrical box, things may need to be slightly repositioned to get everything in or you may need to pull some of the power cable out of the electrical box if there is too much inside.

When you get to testing the outlet, I recommend using something that will validate your wiring. I have seen outlet testers like the one I use for as little as $7 USD and up.

1. Rotate the electrical box so that the face of the outlet is facing up.
2. Align the screws to the holes in the box and begin tightening. Screw in the screws until the outlet feels snug but do NOT tighten all the way.
3. Test the outlet. I use both an outlet tester as well as a USB battery pack that shows power draw to validate the outlet is working as expected.
4. Assuming you don't need to fix anything with the cabling, now is the time to tighten the cable strain relief.

Task - Attach face plate and rubber bumpers

Result - Finished outlet ready for use

In Step 6, you screwed in the outlet. The reason you don't screw tight is that you can use the screws to pull the outlets in closer to the outlet if needed to make them level. You will see in the first picture that the left side of the outlet is slightly higher than the right side. In this case, I remove the face plate, screw in the side I need closer to the electrical box, replace the face plate and check again.

I also place rubber bumpers on the bottom so instead of metal on a wood desk, you get rubber that also helps prevent it from moving around.

1. Place face plate on electrical box and check outlet for flatness compared to the face plate.
2. If needed, remove face plate and adjust screws on outlet to lower one side or the other.
3. Replace face place and screw until snug
4. Turn box over and place rubber feet on bottom.
5. (Optional) With outlet facing up, place weight on outlet for several hours until rubber feet are firmly attached to outlet
6. Enjoy your new 120v Power Outlet with USB ports.