Wiring a Shed

[DerbyDad03]

I am in the process of wiring an 8 x 10 storage shed for a light fixture and an external AC receptacle. The receptacle will be for the occasional power tool, radio, etc. No table saws or anything like that, just small tools and other electrical devices that might be used in the back yard.

Here's my plan and questions:

I currently have a 20A circuit that provides power to a GFCI outlet and 2 light fixtures on my deck, all wired with 12G wire.

The shed is about 15' from the deck.

I plan to run individual 12G wires (Black, White, Green) from the load side of the GFCI to the shed thtough Schedule 40 PVC buried 24" underground.

From there I'll come up through the floor of the shed to a STDP switch which will act as my disconnect. Following the disconnect, I'll go through the wall to a receptacle mounted in a weather proof box under the soffit. I'll mount it high for extra protection from the weather and to keep it out of the snow.

I'll also have a motion sensing switch inside the shed for one, maybe two, light fixtures that will be inside the shed.

Questions:

1 - Does it matter where I put the disconnect switch? Does it have to be within a certain distance from the door or floor? (Obviously I'll put it where it won't get buried behind what's stored in the shed.)

2 - Once the wires come up into the shed through the PVC, can I transition to Romex? If so, at what point?

Thanks!

[jamesgangnc]

I'd ues a regular disconnect myself. They're only about $10 at lowes. Some home and code inspectors will give you grief over the switch. Transition at the disconnect. Put the disconnect a foot or two up from the bottom. SInce it's not serving as a breaker panel the location only matters in that it should be visible from the other electrical stuff. Since you're inside a small shed that's pretty much always the case.

If you use regular romex it needs to be in a location protected from accidental impact. If this is a conventional framed unfinished shed most inspectors will let you nail it to the side of the studs. A few might get anal about it. You could go ahead and use pvc throughout.

[DerbyDad03]

ide quoted text -

Thanks!

By "the side of the studs" I assume you mean the side perpendicular to the walls, not the face that points towards the interior of the shed.

If that's the case, and I have to span several stud bays, what's the best way to accomplish that? I'd prefer that all runs go up to the underside of the top plate and then across as opposed to spanning open areas of the bays where I store "narrow" materials like lengths of trim, etc. However, if the runs go up to the top plate, I can't drill through the stud near the top because of the screws holding the plate to the stud.

Do I just come down a few inches, go through the stud and then back up to the underside of the plate and continue on?

[gfretwell]

Most inspectors would have a pretty lenient policy on a single 15/20a branch circuit disconnect (I would be OK with a 20a rated snap switch) but they might be tougher on the "damage" question inside the shed. Why not just keep going with the RNC at least up to the ceiling.

[dpb]

On 9/19/2011 10:18 AM, DerbyDad03 wrote: ...

Do whatever works, basically.

I can't imagine there are so many or so large of screws there's not room enough for a hole large enough for a single run of Romex wherever it's wanted, basically.

I'm partial as another says to run conduit, anyway

[jamesgangnc]

Last time I looked a 20amp switch was about as expensive as a disconnect in a metal box. Disconnect in a box $7.68 at lowes. Why not?

[DerbyDad03]

Well, since the shed was built from a kit with 2 x 3 studs, there isn't a lot of room on either side of the screws to drill a hole - assuming I knew exactly where the screws are - fairly centered, I hope! ;-)

As I plan the actual layout of the switches and fixtures, I'll figure it out as I go along.

Thanks!

[DerbyDad03]

I'll look into that.

Another question related to the disconnect:

Whichever option I choose, can I run multiple wires directly from the disconnect or do I need a junction box?

In other words, after the disconnect I want the receptacle to always be live and have the light fixture controlled by the motion detector. Can I attach the wires for both runs to the output of the disconnect or do I need to use a junction box after the disconnect and then branch off from there?

[trader4]

e quoted text -

If the routing will accomodate, I'd go from the disconnect to the receptacle to the motion detector. If you want to feed two runs off the disconnect, I think you could do it. Seems there is quite a bit of spare room in the one I last installed and don't know of any code it violates. But if you do, you should not put two wires under the screw down terminals. I'd wire nut the two together into one wire going into the disconnect terminal.

[Harry K]

ide quoted text -

Why not use romex for the underground run. It does come in direct burial. Might be cheaper to buy a 12-2 WG romex than individual wires.

Not an electrician but my run would be Disconnect - double box with duplex outlet and a switch for the lights. Evem of they are motion dectectors it is best to wire them through a switch - some require a switch to reset them if they fault to constant on. Any additional outlets come off the outlet in that first box. Of course the right way (as I understand it) would be the feed into the shed into a subpanel and go from there. But that would be if the circuit started in a panel.

Harry K

[jamesgangnc]

Hide quoted text -

I try to use pvc for burial. Most places let you go a little less down but for me the big plus is not having to deal with an underground splice when I forget the wire is there and the wife has me digging a hole there for a plant.

[gfretwell]

He can use UF, cable similar to Romex (actually a brand name for type NM-b a dry location only cable). I am not sure it would really be cheaper and he will be locked into the wire size he runs if his needs change. Personally I would run 3/4" conduit since the difference in price from

1/2" is minimal, your pull will be a lot easier and that will leave your options open.

The best way to go is to use an LB conduit body where it transitions into the building, That splits up your pull a little and makes it easier going. You will usually just have 2 bends then. I like to suck some pulling lube through the pipe with my shop vac before I start (squirt it in one end and suck it out the other) while you are sucking the pull string through. Then squirt some in the other way as you are pulling the wire back.That will make your pull go very easily.

[DerbyDad03]

Hide quoted text -

The motion snesor will be of the style that has a switch like they have in the conference and rest rooms where I work, not just a "remote sensor" like you would have for a securty light.

Thanks for your other suggestions.

[clare]

The disconnect MUST be reachable from the open door, and you can transition to Romex from any junction box, which must be left accessible, providing the romex is protected according to code. Myself? I'd bring the conduit right up to the disconnect box.

[clare]

quoted text -

The disconnect will function as the switch to reset the motion detector, so why add another switch?

[gfretwell]

That may be a Canadian thing about the door but in the US it is supposed to be right where the wire enters the building. Generally you will come up out of the ground to a reasonable inside switch height on the outside, LB through the wall and set a box and disconnect on the inside. You can then fan out your circuits from there. Again the inspector would usually have some leniency if you came up the inside wall in conduit directly to the switch. After all, these are not service conductors. and he is on the load side of a GFCI. Personally I think a single circuit to a residential shed should not need the disconnect at all but I didn't write the code, I just have to enforce it.

"225.32 Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in

230.6 shall be utilized."

[dpb]

On 9/19/2011 11:41 AM, DerbyDad03 wrote: ...

...

OK, wasn't thinking of the reduced dimension, but I'd drill the hole where I wanted it and if that means driving another fastener later because I hit one, so be it.

--

[aemeijers]

Good thing I'm not allowed to hit Usenet from work. I think your description would set off the NetNanny alarms they have, based on too many buzzwords for dirty stuff. :^/

[DerbyDad03]

I came up inside the shed and the conduit currently runs about halfway up the wall inside a stud bay. That's where I stopped until I checked out how to proceed.

How about if I continue the conduit up that stud bay and put the disconnect near the top plate so that it won't be blocked by items stored on the floor? The top plate is 6' from the floor and I could reach the disconnect after taking one step into the shed. A taller person could probably reach it from the door.

From there I can fan out to my receptacle and light switch.

Sound OK?

[DerbyDad03]

No need to discuss conduit vs. UF since I already ran the conduit and pulled the wires. I now know I should have used 3/4" instead of 1/2" so I'll count this as a lesson learned. :-(

Next time...