So I don't want to waste your guys' time, so I'll keep it simple.

Setting: North Richland Hills, residential home, shed is metal, backyard is fairly spacious, shed is 40 feet behind the house, the garden is behind the shed, no trees above the wire-to-be-run.

Goal: My grandparents really want to have lights out in their victory garden behind their house, they also want to run electricity in the shed they had built a few years back. So from the house, to the shed, out to a pole that will have lights on it for their garden.

Requirements: I want to keep it within code for NRH, however I have absolutely no clue where to find those codes. I have been searching for two days, nothing to show for it, which is why I turn to you guys. He wants to run 7 lights at least, 4 halogen spotlights and 3 fluorescent shop lights. Wattage not decided on yet. We will be running tools in the shed, namely a drill and a skill saw. Not at the same time. Thats it when it comes to amp draw, nothing else.

My Issues: I have only ever done modest DC applications of electrical wiring. I know a lot about AC/DC principles and electrical engineering concepts, however I know absolutely nothing about electrical work within codes and 120v AC applications. I can, however, learn how to, and want to.

OF NOTE: My grandpa is fairly stubborn and he wants to set up a pole half way between the shop and the house, and send an already bought home depot outdoors AC cable, 20A, UF/UV resistant cable across to the pole, then the shop. He doesn't want to run a steel support cable. The pole he bought would be 10 feet off the ground after we install it. This I am pretty certain would violate codes, since it has to be 12 feet off, especially since he would drive under it with his minivan.

What I Have Heard: Underground > Overhead, however we have a tractor with a plow, and he is scared he might pull up on the wire accidentally if we did that... We need a breaker at the shop to kill power if need be... We need to run a new circuit for the shop itself, with a 20a circuit breaker... We need to use a certain type of cable and conduit for underground applications... IF we do it overhead, it must be run with a support cable, I have no clue how to tighten or install one of those.

What I Can Do: Interior AC installation, e.g. outlets, I have done before.

Hopefully this is enough information that one of the experts on these forums can point me in the right direction.

 

I don't know the codes in Texas either but I would say that underground would be better & you'll probably need a sub panel, in the shed. I'll leave the rest to someone who knows the codes better than I do.

 

Thanks, I'll try to get him to switch plans!

 

Up to about a hundred feet away the underground cable method is pretty standard, direct bury cable (such as style UF) at least 24 inches deep or conduit with style THWN conductors at least 18 inches deep. Wet rating of wires or cable is the key.

A major part of the work is digging the trench. Because of that, for futureproofing, most experts recommend #6 gauge (60 amps) for two hots and neutral (and #10 gauge for the ground) or 6-3 cable with ground. For a really small shed, #8 gauge (40 amps) will do. You don't need to install the subpanel out thereyet as long as you have breakers of no more than 20 amps back at the main house for now.

You will need a master switch at the shed, which switch could be the top breaker of a subpanel or a separate 2 pole 240 volt switch in a separate box.

 

What about the pole in the garden?

 

#6 seams a bit overkill in this installation. More power is always better then not enough but I would lean towards a 30 amp 120/240v feeder using 10/3 UF with ground. A small sub panel (6 circuit) and ground rod should work fine. This should be buried at least 24" down with PVC (gray) as risers from the 24" to protect the cable.

UF can not be run overhead without a messenger support wire, and as you mentioned, needs to be higher then 18.5'

 

So when I dig this trench, EDIT: I will look this up instead of asking. EDIT: you probably misphrased that, you mean the sub-panel and rod should be used, and all of the other stuff should be buried underground.

 

I think a 20 amp 120 volt single or MWBC would more than serve your needs. You could bury a 12-3 UF cable and have two circuits to work with, one for lighting and another for the tools. No rod or subpanel needed.

 

What is the reason for putting in a grounding rod for the shop? I understand the need for a subpanel.

 

If the outbuilding is served by a feeder, not a single circuit the code requires a grounding electrode system.

 

So these terms 'feeder' and 'single circuit' Im guessing mean:
Feeder : only two wires, hot and neutral?
Circuit : three wires, hot neutral and ground?

 

No, a feeder goes to a panel.

 

Ah, ok. Thank you.

So underground is the obvious winner here, 30a cable, UF rated, I will probably go with conduit at 18' deep, and will run two separate cables for the two different applications. One will go to the outlets and the florescent lights (plugged in via outlet) and the other will just continue to the other side of the shop and run the halogen spotlights. Would I need a disconnect at the shop? The house has the circuit breaker facing the shop (very close to it) within 40 feet.

Oh and i totally forgot to mention, there is a sewer line very close to where I would be digging...

Now, my grandpa being stubborn still wants to do it overhead, even after I offered to do ALL of the work. What would be required to do that? And how would I tighten that support cable? The wire he bought is UV rated 20a.

 

Best practice is to not use cable in conduit. In conduit you would run individual conductors (wires) such as THWN.No you can only have one feeder to a building.

If you want to use conduit and have two circuits you would need to run a multiwire circuit as suggested by PCBoss.

• You would use either a 20 amp 240 breaker in your main panel or two handle tied 20amp single pole breakers in your main panel.
• You would run in PVC conduit two black (or one black, one red), one white and one green #12** THWN wire.
• At the shed they would go to a disconnect* and from the disconnect be separated into two 120 volt 20 amp circuits.

*The disconnect could be a 2-pole switch in a 4x4 junction box but convenience and cost wise a pull out 60 amp air conditioner disconnect makes the most sense.

** Assuming you are running a multiwire circuit 20 amps is the maximum so you only need #12. You could future proof using #10 which if you needed more circuits later would allow you to convert to a subpanel.

 

Well all this is, is a lot more complicated than I thought it would be, what is the simpliest solution? Just one conduit with THWN conductors out to a panel, with a ground?

 

No the one for a multiwire circuit I outlined is easiest.

 

Well i guess that means no diagram, ty very much for the help. I'll have to do more research on the lingo / techniques before i do this.

 

If he is that stubborn, forget about it.

 

It can be done overhead but I think that he is thinking of individual conductors the way it used to be done but the individual conductors such as THWN that are readily available can't be used because they are not UV resistant. Most easily available would be sunlight resistant UF cable but that requires a messenger wire to support it.

Either way here is a crude diagram of the multiwire circuit you would use.

 

So no grounding rod needed? That looks alot simpler than I expected
TY for the diagram, btw

 

Grounding rod is not needed because there is no subpanel.

 

Exactly what cable did he buy? If it is 12-2 UF-B cable it would only be good for one circuit anyway, probably not enough for what you want to do. If it is 12-3 UF-B cable it could be good for two circuits as a multiwire branch circuit. I believe he could return it and let you buy what is really needed.

 

May I ask what country your grandfather is from & would he understand the phrase 'testa dura' ?

 

I'll get the specifics of the cable, one moment, and Pulpo, Germany.