Electrical to shed questions

[ctandc]

I'm in the planning stages of a 12x12 shed. I want to run electrical to the shed.

The shed is just for storage, as it's purpose is to clear out my garage, where I do all my work. So I only need a couple of outlets (mainly for the battery tender for my riding mower) and a couple of light fixtures.

It's about 30-40 feet from the shed location to the main electrical panel at the house. I have plenty of room to add a circuit.

Should I add one or two circuits to the house panel?

Do I need to install a sub panel at the shed with a breaker or breakers?

Will I need to install a grounding rod at the shed?

What type of wire will I need to run and will enclosing it in PVC be okay, or is there a wire designed to be buried without PVC?

18" deep enough for burying the wire?

Thanks for any help.

 

[mrb]

if you run one circuit you dont need a subpanel, disconnect (unless local code says otherwise) or ground rod. Personally I would run THWN wire in PVC conduit, but you can use type UF direct burial cable. Dont put romex (NM-B) underground, in conduit or not.

 

[Charles (in GA)]

To clarify, you cannot have more than one circuit between buildings (one circuit being, at the most, two hots, a neutral, and a ground, making up a 240v feed). You cannot run two independent 120v circuits, such as one for lights and one for outlets. You can run a multiwire circuit (which is wired from the house to the shed no different than a 240v circuit)

Remember, you must supply a disconnect at the shed for the incoming circuit.

Charles

 

[Rosco]

Should I add one or two circuits to the house panel?

I would add one circuit, probably a 30 amp breaker minimum to a small sub panel. Why dig a trench for less?

Do I need to install a sub panel at the shed with a breaker or breakers?

You do not need to but I would. If you are going to dig a trench, why not bury a large enough wire for other uses in the shed?

Will I need to install a grounding rod at the shed?

A pro will chime in here, but if you run 10/3 or 8/3 to a sub-panel I dont think so. Again, a real electrician will chime in.......I just play one sometimes

What type of wire will I need to run and will enclosing it in PVC be okay, or is there a wire designed to be buried without PVC?

Even though you will encase it, it still should be rated for underground.

18" deep enough for burying the wire?

Check your local codes



I have learned from this board to always plan on future expansion and future needs. If you are going to dig a trench, make sure it is deep enough and has a large enough wire for future use. You can always use less power from a larger circuit but not the reverse. Next year you might want a flat screen and cable

 

[mrb]

anything beyond one circuit and you need grounding electrodes. So if you install a subpanel you need grounding electrodes (two ground rods 6ft apart). Unless you know you are going to have heavy power requirements over there just run one circuit. If you think you might need more power out there later run larger conduit (1-1/4") so you can pull in a feeder later...

 

[richtersrodz]

I ran a 12/3 circuit to my garage, and only used one part of the circuit. Also put in a
small junction/breaker box in the garage. I didn't want to have to run, out of the garage,
over to the box, fiddle with the cover, just to flip the breaker.. So I figured that the
breaker in the box in the garage was a good plan. I did do one thing that others have said
not to do, and that was run romex through grey conduit. It was a pain in the *** to pull,
and would bind up going around the corners... So I can see why you wouldn't do that
now..

But is that the only reason why you don't pull romex through pvc conduit?

 

[mrb]

I ran a 12/3 circuit to my garage, and only used one part of the circuit. Also put in a
small junction/breaker box in the garage. I didn't want to have to run, out of the garage,
over to the box, fiddle with the cover, just to flip the breaker.. So I figured that the
breaker in the box in the garage was a good plan. I did do one thing that others have said
not to do, and that was run romex through grey conduit. It was a pain in the *** to pull,
and would bind up going around the corners... So I can see why you wouldn't do that
now..

But is that the only reason why you don't pull romex through pvc conduit?

conduit in the ground is a wet location. romex isnt rated for use in wet locations thus it isnt permitted in a conduit underground.

If you put a breaker panel in the garage, now your circuit is a feeder and you (are supposed to have) need a grounding electrode, and I think there are some minimum ampacity requirements (someone else (hopefully that knows what theyre talking about) can chime in on this)

 

[richtersrodz]

Gotcha.. It was a long single run, no cuts in the run, about 25 feet. With a small single
breaker inside of the garage. Then I ran plugs and lights from there.

I would have done it a bit differently, if I had a chance to redo it, or at least put in the
proper grounding rod setup. I grounded back to the main box.

 

[VHF]

18" deep enough for burying the wire?

• If you run conduit, then 18".
• If you direct bury UF cable, then 24".
• If you direct buy UF cable and provide GFCI protection at the source, then 12" is sufficent.

Disclaimer: These are generalizations!

For just a few lights and a battery charger, running a single 120V 20A circuit would be the easiest and least expensive, using either conduit or UF.

 

[VHF]

if you run one circuit you dont need a subpanel, disconnect (unless local code says otherwise) or ground rod.

I thought current NEC code (since at least 2008) called for a single point of disconnect at the shed even with only a single 15A/20A circuit feeding the shed. Is that not an NEC requirement?

Some people have used a 20A SPST switch (heavy duty light switch) as a disconnect at the shed.

 

[MoonRise]

Step One : Find out what (if any) Code and/or Permit requirements there are for your area.

Step Two : Follow those requirements.

As mentioned, "Romex" (actually that is a brand name for one brand of a type of cable, sort of like Kleenex for "tissue" or Xerox for "photocopier", etc) or more 'correctly' NM-B (used to be just "NM" and then they changed the 'specs, so now "NM-B") is not rated for use in "wet" areas. And conduit in the ground is -always- considered "wet" (and it usually is!).

IIRC, if you run one "circuit" to an outbuilding, then you don't need to have grounding rods at the outbuilding. YMMV. If you run a 240V subpanel to an outbuilding, you have to run four wires (hot-1, hot-2, neutral, and ground) out the the building and have ground rods. Among other things. Again, YMMV.

Find out what is required in your locale, electrical-wise. Then go from there. (Hey, they may have a requirement that -if- power is run to an outbuilding, then lights -and- circuits are required to be separate, which means you pretty much have to run four wires plus ground rods and a subpanel. Again, YMMV.)

 

[richtersrodz]

So I have a dummy question here.. If I have NM-B cable, that I want to run to a storage
shed, I'm not allowed to run it? Because it is not suited for straight bury, and I'm not
supposed to run it in conduit.. So either run separate wires in conduit, or buy bury cable
only? I just want to educate myself for later down the road, when I want to do this again.

 

[richtersrodz]

if you run one circuit you dont need a subpanel, disconnect (unless local code says otherwise) or ground rod. Personally I would run THWN wire in PVC conduit, but you can use type UF direct burial cable. Dont put romex (NM-B) underground, in conduit or not.

Just re-read this again.. and answered my own question..

 

[dittle fart around]

The cool part of direct burial wire is you don't have to dig a trench.
http://www.toro.com/en-us/rental/co...ies.aspx?sid=Vibratory-Plow-Boring-Attachment.
We ran 300 feet of 10/2 direct burial to a score board at the little league and played on the field that night.