How to power a new shop

[Matt Benton]

I've decided to use our 11 x 15 building in the backyard as my shop. Pier and beam, bare studs and no electricity.

I need to get electricity to the building. I have a breaker box in the garage that's on a 50 amp circuit in the house. I'd like to take a 20 amp 220v circuit from the garage and send to a breaker box in the shop. I'll only need it for lights, 110v bandsaw, 110v drill press and small power tools (drills, etc.). My 220v machines will stay in the garage.

Question is, can I run Romex from the garage breaker box to an outlet on the outside of my garage, and put an outlet on the outside of my shop, and connect the two with an extension cord that I could unplug and roll up when I'm not in the shop? I doubt this conforms to code, but curious if it would be functional, assuming the extension cord was appropriately sized. Underground is not currently an option. Total distance from garage breaker box to shop breaker box would be about 50'...

Thanks!

[Anthony Whitesell]

I don't have the voltage drop vs distance tool handy. So I can't tell you the amperage or voltage loss after 50 feet of 12g cord. But I know that you won't get 110V or 20A out the other end. You'll need an extension cord that is at 10g (if not larger) to run 50 feet and pull close to 20 amps.

[Matt Benton]

Anthony,

Thanks for the reply. I'm planning on 8g romex in the garage and shop, and an 8 gauge welding extension cord between buildings.

I was also thinking that the extension cord could be wired directly to the breaker box in the shop, which should reduce some loss by having only one outlet connection, instead of two...

[Ron Natalie]

Running an extension cord into the permanent wiring or using it in lieu of permanent wiring is illegal in most places.
There isn't hardly any resistance/voltage drop at the receptacle itself, it comes from running a given current through a distance of wire.

To do this legally requires a legal, wet location wire for whatever means you're using (underground or aerial) between the building, If you run more than one circuit, (you can probably cheese it with 220 V multiwire branch that you pluck the two 110 legs off), you'll need to put in a proper grounding system in the outbuilding. You'll need four conductors (two hots, ground, and neutral) which most extension cords don't have either.

[Matt Benton]

Maybe something like this?

http://www.molex.com/woodhead/produc...cts&Lang=en-US

[Rod Sheridan]

Ron has the correct answer, an extension cord cannot be used in place of permanent wiring.

Unless your buildings move in relation to each other you need to run a proper feeder between your buildings.

Regards, Rod.

[Steve Meliza]

Yes, it would work electrically speaking, though you would need to find or make an extension cord with male plugs on both ends. However, if you do so you'll violate code for sure and if you ever had a fire or someone got hurt as a result of your non-compliant electrical work your insurance company may not pay out and you could even face legal charges and civil lawsuits if someone was hurt.

To me it begs the question why not just run a couple 50' extension cords from GFCI outlets in the garage? If you're willing to set out and roll up one power cord then two that are zip tied together isn't much more trouble. Of course the problem being you'd need power splitters on the far end and would have to plug in each of your lights and tools. A power strip for the lights would help though.

[Anthony Whitesell]

I was thinking of something along the lines of a generator cord set. I know all the connectors for the cable and the boxes are available in both male and female. You could just make a cord (SO cable 8g) with the 4 prong 220V plug on one end and a "break out box" on the other. (double duplex outlets in a 4x4 deep box). It will be a little lacking on the water resistance.

[Matt Benton]

Sounds like the water may be getting a bit murky with respect to code (not that I would know).

Can you power multiple devices via extension cord, if that cord provides all the power to a stand-alone building, including it's overhead lighting?

[Anthony Whitesell]

In that case you can probably find a pre-made generator cable long and heavy enough.

You're not really "in code" so you can do a lot. Extension cord routinely power multiple tools by having the 3 way plug on the end. With the gen cord set, you have two sets of 120. One for lights, one for tools?

I'm thinking this looks a lot like an RV setup with the shed not having a foundation or being permanently located (yes, moving it would be difficult but not as much as having a foundation). The shed could be wired similar to an RV. I think the situation is pushing the limits in the event that some happens.

[Ron Natalie]

Oh, well if you're not concerned with the same or legal way to do it, I doubt I'll be able to help.

[Matt Benton]

Ron, the fact that other people are offering me non-conforming solutions does not mean that I am actively seeking them. You're responses help me by adding to my knowledge on the subject, whether I follow your advice or not....

I guess my question has evolved, as they often do during conversations. I find it interesting that power can be run to an RV, and multiple devices within the RV powered from a single temporary power source (ext. cord), but not so with a building. Is the RV's portability relative to the building the determining factor?

Thanks to all who have responded....

[Rod Sheridan]

Is the RV's portability relative to the building the determining factor?

Thanks to all who have responded....

Absolutely, hence my comment about not much movement between buildings.

Flexible cord is allowed between moveable objects (obviously, otherwise your toaster would be hard wired), or where there is relative motion (your tablesaw motor tilts).

It cannot be used as a substitute for permanent wiring, which is what you're trying to do.............Regards, Rod.

[Don Jarvie]

If you want to do it right dig a trench and run the line though conduit from the garage to the shed. Put in a subpanel and put a 50 amp breaker in it with a 50amp breaker in the box in your garage. This way you can run a few lines in the walls and have some juice set up. You would probably only need to dig down a foot or so.

The conduit will be water tight and you can have the right size wire to power the shop. You can go up to 50 amps but no reason you cant put a 30 or 40 amp breaker out there. You can also kill the power to your shed via the panel in the garage.

The "extension cord" setup may sound good now but you'll probably want something more permanent in the future so start digging.

[Phil Thien]

I'd think a 50' extension cord of sufficient gauge to carry the juice you will need would be a pain in the you know what to roll out every time you want to do something in the building.