Latest Discussions : Electrical & Lighting


07:25PM | 10/09/04
Member Since: 03/24/03
5 lifetime posts
Yet another shed circuit question. I want to run a 20 AMP circuit to my shed (120 foot run from the main electrical panel) to power some inside lights (3 max), an external security light (not switched from the house), and a couple of outlets. I plan on using PVC conduit.

1) Can NM-B sheathed electrical cable wire be run in the conduit, or do I have to use individual conductors?

2) Given the distance what size wire needs to be run? (I am also considering a 15 AMP circuit, as the lighting is the primary need in the shed). Also, can I reduce the wire size to 12 gauge (or 14 gauge) for internal wiring?

3) Is a GFCI breaker at the main panel needed? (I'm thinking yes).

What else am I missing here?


Tom O

05:47AM | 10/10/04
Member Since: 09/17/02
476 lifetime posts
1. Absolutely not. Single conductors, such as THWN will do the trick.

2. #10 copper would allow you to fully utilize this circuit. Use #12 wire in the shed, stick with a 20 amp circuit, I don't see any advantage to doing all this work & only putting in a 15 amp circuit.

3.If you opt to use a GFI at the panel, you could reduce your tranch depth. In this case you would only need 12" of cover. The only part of this installation that actually needs GFI protection are the receptacles.

You must have one switch at your shed that shuts off all power.



02:32PM | 10/10/04
Member Since: 03/24/03
5 lifetime posts

Thanks for the info. I've got 2 quick follow-up questions.

1) Any grounding rod required?

2) Any requirements for the location of the disconnect switch? I plan on bringing the circuit into the shed on the opposite side of the entrance door.

Tom O

11:40AM | 10/11/04
Member Since: 09/17/02
476 lifetime posts
1. Ground rod is not required in this case.

2. Disconnect should be "nearest the point of entrance" so just bring your conduit up to a junction box & install a regular switch for the required disconnecting means.


02:31PM | 11/10/04
Member Since: 11/09/04
1 lifetime posts
I'm doing a similar stunt, but I figured that I'll put 2 circuits out there while going to all of the effort.

-- going to my detached garage, which is 15 fee from my house (30 feet from where the circuit will come out of the house).

-- Two 20 amp circuits from my main panel.

-- Six #12 wires in the pvc (2 blacks, 2 whites, 2 greens)

I'm wondering about what exactly the service "disconnects" must be? The guys at the electric supply keep thinking that a sub-panel is what I'm asking about. That would mean that I'd be putting 2 additional 20-Amp breakers on the circuit (I can't figure out why). Another guy said that I needed to have a disconnect that uses a pull-out block.

Would 2 commercial grade 20-amp single pole toggle switches suffice? Is the fact that I'm doing 2 circuits an issue?

I'm going to put GFCI Outlets at the beginiing of the runs.

Tom O

11:40AM | 11/11/04
Member Since: 09/17/02
476 lifetime posts
Yes, 2 circuits is an issue.

Here is the work around. Get rid of one white wire and one green wire. This leaves you with 2 hots, one white, one green. Make sure that you connect the 2 hot wires so that they are not on the same phase. They should have 240 volts between them. This is called a multiwire circuit and it counts as the one allowed circuit. At your garage, install a 2 pole 20 amp light switch as the required disconnecting means. Any GFI protection you put in will need to be in the garage after the switch.



06:48PM | 08/11/05
Member Since: 08/10/05
2 lifetime posts
I'm planning the install a new "panel"(i'm a mechanic and i'd usually call it a breaker box) in my separated shed/garage. the reason for installing the panel is i'm planning on installing a compressor (240v), a few outlets and lights(typical automotive stuff). the main service panel is about 60 feet away from where the new subpanel will be. 18 feet of that distance would have to be hung overhead (concrete driveway will not allow for any trenching). 1st question: what size wire will i need , i was thinking #8 or #6. 2nd question: what kind of wire or conduit do i need in between the buildings? 3rd question: can anyone point out a good step by step site or give a good description on the actual overhead wiring???

thank you



07:08PM | 08/14/05
Member Since: 08/13/05
1 lifetime posts
Basically I have the same question as Mechanic .. I am installing a sub panel in my garage .. for the same reasons ... compressor, additional electrical outlets. I plan on putting in a 100 amp sub panel off of my 200 amp main service panel. The garage is located about 60 ft from the main. What size breaker do I need to use on the main panel for the sub? What size wire do I need to run the 60 ft distance? Do I use Aluminum or Copper wire? TIA Frank


08:19PM | 11/22/14
what kind of disconnect i can use to power 2 circuits to my shed


08:23PM | 11/22/14
i have 10/3 pull to my shed already with everything already pulled just need to know what i need to power my shed coming off my 220 amp service


08:22AM | 10/23/15
i have no idea how to or what i need to do for a blown plug fuse in my shed, i bought 20 volt fuses there both the screw in type so i pullede the lever to OFF and screwed in the fuses it still doesnt work... what am i doing wrong?


03:27PM | 06/23/20
Member Since: 06/23/20
1 lifetime posts
I am running 240 VAC 10/3 circuit UF cable to a shed for about 125 ft
The idea is to add 30 amps sub panel of course for 20 amps breaker and from there rewire pool pump to 240 v and few lights.
Any help about it so I do the right thing.


10:41PM | 03/14/21
I have been reading upon running 20 amp switches to sheds. I have a very similar situation here. If I could get some help it would be greatly appreciated.

My shed is about 110ft from my main panel which is inside my garage. I would like to dig a trench 18" deep (which is code) from the outside of where my main panel is located to the shed.

I would like to run three 20 amp switches to my shed using PVC conduit 1" underground. I would like to run three separate conduit wires (10g or 12g) to feed three separate switches connected to GFCI for security inside the shed.

I plan on running a miter saw, table saw, air filter, about 10 outlets in various places.

Any advice as to how I can do it. I read that you can run 10g from main panel to inside shed and then run 12g inside with the 20 amp breakers??

Please help!!


04:27PM | 08/28/21
when you say "nearest the entrance" and I have a deck at the entrance, can I put the cutoff switch off to the side of the deck to look less apparent than drilling holes in deck and attaching beside entry??

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