My 14 by 32 shed will be ready to go in a couple of weeks and I am trying to figure out what size wire I need to run from the panel on my house to the shed. It will have 6 110 outlets,1 220 outlet and 2 light outlets. I will primarily be running power tools and a air compressor that is 110. The 220 will be used to run a welder in the future.

What is the distance the cable or conduit will run? Need to consider voltage drop.

200 Ft

How big a welder? I've seen some real power hogs.

Just to get 50 amps 200 foot at 120/240 volts, you will need at least #1/0 aluminum. This is an odd size wire and may not be available.

I will recommend that you use #4/0 Aluminum 4 wire URD cable, which is readily available, reasonable cost, and can be direct buried. This size can deliver 100 amps at just below the maximum 3% voltage drop.

If the soil is rocky, or if you want additional protection, you can use 4" PVC DB conduit to sleeve the cable.

Attachment 5499

I have attached a picture of my outside panel that I will be running the power for my shed from. I need to make sure I understand what is going on in the box because I think it could have been done better. The three wires coming in from the meter are two hots and a neutral or is it a ground?

The wires running to my panel inside the house are as follows and correct me if Im wrong: the red and the black are hot, the solid copper is a ground and the bare silver is the neutral. If I am right can you tell me if its good for the neutral not to have an outer casing.

If I am right on the above lets move on to the new wiring for the shed. I am going with your advice and running 3 wire 4/0 aluminium with a 2/0 ground. How should I wire this into the out side panel? I know the two hot wires will go to the breaker. Were should I attach the neutral and ground in the out side panel? Should I purchase two more post and attach them to the same bar that the ones for inside house panel are attached to? And for the panel in my shed should I install a ground bar or should I wire them into the same bare like they are in the outside panel? It is also like that in my inside house panel.

Looks like someone made up a 4 wire feeder by adding a separate wire as the equipment ground.

The cable should have a connector as it enters the box.

All neutrals and ground will connect to the bar in the box with the Main. Feed ting shed with four wire, keeping the neutral separated from the ground at the panel, and drive a ground rod to ground the equipment bar.

Just to clairify I need to connect the neutral and ground for the shed to the same bar as the copper and bare silver wire is connected to in the main box.

Yes, exactly, and get a connector on that cable. It shows evidence of shoddy workmanship.

Can Neutral be Bare?

Ever see 3 wire SEU cable?

Two insulated wires and one bare, to be used as a feeder to a serivce, and yes, available in both aluminum and copper.

Also, ever see three wire aerial triplex cable? Again two insulated hots and one bare neutral.

Read Article 200 use and Identification of Grounded Conducotors, Section 200.2, and I quote "The grounded conductor, where insulated...."

And refer to Section 230.41 Exceptions


The picture shows a poorly installed, or an after thought, with the 3 wire SE cable, and then the equipment ground run separately.

I would fail this installation and demand a 4 wire SE cable be installed.

As I said, shoddy workmanship.

But the neutral may be un-insulated in any case.

I learn something everyday, Thanks. Personally I wouldn't do it. Old Habits?

Note the sections I refer to, there are only a few exceptions that allow bare neutrals, all having to do with service entrance feeders.

And, of course, since you are from south Fl, on the ocean, where no aluminum wire is allowed, I doubt anyone there would see this practice. But the rest of the country , this is very popular.

When you say replace the connector are you referring to the lug that the bare neutral is attached to?

No, I mean install a two screw squeeze connector on the large cable as it enters the metal box.

This is basic 101.

Makes me wonder about the quality of the rest of the installation.

Thanks for all the help. Just to set things straight I have never wired a breaker box and that is why I have all the questions and as you can see I did not have a very good example to go by. The work in the picture is not mine. This is what the builder left me with and now with your advice I will probably switch over to a 4 wire cable and do it the right way.