Electrical Wiring: How to Run Electrical Wire Outside

The easiest way to bring electricity to a shed, garden or lamppost

Fourth dimension

A full 24-hour interval

Complexity

Intermediate

Cost

$101–250

Introduction

Learn how to run electrical wires outside underground to reach sheds, lights, patios and other locations, post-obit safe wiring practices.

Tools Required

Materials Required

  • Duct seal
  • Electric boxes
  • Electric tape
  • EMT (electrical metallic tubing)
  • Fish record
  • Fittings (connectors and LBs)
  • GFCI
  • Leather gloves
  • Mattock
  • Pipe bender
  • RMC (rigid metal conduit)
  • Stranded electrical wires
  • Switch
  • Ii (white and blackness) conduit straps
  • Wire connectors

Overview: Project Scope, Special Tools, Materials and Costs

Dragging extension cords across the g to power the string trimmer, fumbling around in a dark shed…most of u.s.a. take these hassles for granted. But it doesn't have to be that way. With a day's work, you lot can run electrical lines to whatever role of your g.

This article will evidence you lot how to bring power to a shed, but the process is almost identical if you want to only mount an outlet on a post planted in the soil.

A licensed electrician would charge at least several hundred dollars plus materials to run lines from your firm to a shed fifty anxiety away (not including any work within your house).

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Running Power Through RMC

We'll show yous how to run wires through rigid metal conduit (RMC). This method offers the all-time protection of the wiring and requires the least amount of excavation. Information technology too lets yous install a GFCI outlet at the terminate of the line rather than at the house, which means you'll never take to run back to the house to reset a tripped GFCI.

If you lot desire to provide a dedicated circuit to the shed, hire an electrician to make the final connexion in your main electrical console. Otherwise you lot can connect to an existing circuit if the circuit has enough capacity and the box you're connecting to has enough volume for the additional wires.

Running Wires Inside Rigid Conduit

To run the wires inside rigid conduit, you lot'll need a hacksaw, a pipe bender capable of bending ane/2-in. rigid conduit with an outside diameter of three/four-in., and a fish tape long enough to reach through the buried pipe.

You'll also demand a pair of pipage wrenches to spiral the sections of pipage together, a drill and i-inch bit capable of penetrating your siding, and wire cutting and stripping tools.

A few weeks earlier y'all start the project, contact your local building department to obtain an electrical permit if one is required. And so a few days earlier you dig, phone call 811 to accept your hush-hush utility lines marked. Learn more at call811.com.

Project step-by-step (12)

Stride ane

Using Metal Conduit Means Less Excavation

  • Running wires within rigid metallic conduit (RMC) is a little more expensive than burying secret feeder cablevision (UF), but it saves labor.
  • This is considering the top edge of RMC has to exist only six inches below the surface of the ground, while UF must exist buried 12 inches deep (deeper in some situations).
  • That extra six inches of trench depth may not seem like a big bargain. But it adds hours of backbreaking piece of work, peculiarly if y'all have rocky soil, hard clay or lots of tree roots.

Metal Conduit Means Less Digging

Step 2

Plan the Conduit Route and Dig the Trench

  • Use a mattock to dig the trench. The narrow head ways less dirt to remove and less to put dorsum.
  • Piece out strips of sod with a spade so you can neatly patch the lawn later on.
  • There are several factors to consider in planning the road from the house to the shed.
    • Evidently the shorter the trench, the less digging you'll take to do. Simply yous likewise have to determine where you're going to connect to power inside the house and how easy it will be to become there.
    • In some cases, a little more digging could relieve you from having to tear into a basement ceiling.
  • Start by locating a power source, whether it's your chief panel, a ceiling box, outlet or other electric box.
  • Then effigy out the best spot for the new conduit to enter the house.
    • Pro tip: Since the National Electrical Lawmaking (NEC) limits the number of bends you tin can brand in the pipe to a total of 360 degrees, you have to programme the route carefully. The two 90-degree bends from the ground into the house and shed swallow 180 degrees, leaving you 180 degrees more for any additional bends.
  • With the route planned, you tin can measure for the corporeality of wire and conduit you need and head to the hardware store or home center.
  • Add 10 anxiety to the length of wire and pipe to brand certain you'll have plenty.
  • It'south smart to drill the hole into the house before you start digging just in instance you run into an obstruction and have to cull a new location.
  • When you're certain of the exit point, dig a trench from the house to the shed.
    • Pro tip: If y'all're going across a lawn, remove a piece of sod the width of a spade from the surface and set it aside to reuse after you coffin the pipage.
  • Then use a mattock or narrow spade to dig the trench.
  • Pile the clay on plastic tarps then you don't accept to rake it out of the grass later.

Plan the conduit route and dig the trench

Step 3

Mount the LBs and Metal Boxes

  • The rigid conduit will come out of the ground and into a fitting called an "LB."
  • The LB has a removable cover that simplifies the task of pulling wire by eliminating a sharp right-angle turn.
  • The trickiest part of this projection is mounting the LBs and connecting them to metal boxes inside the business firm and shed.
  • In general, you'll have to choose a box location and then calculate the length of electrical metallic tubing (EMT) needed to achieve from the back of the LB to the box.
    • Pro tip: If you lot're going into a basement or crawl space, the length of the conduit usually isn't critical.
  • Start by drilling a small hole with a long bit to brand sure you're in the right spot.
  • So drill a one-inch pigsty for the LB and conduit.
  • Screw a ane/2-in. conduit connector into the dorsum of the LB and then attach a piece of 1/2-in. EMT that's long enough to reach an easily attainable box in the basement or clamber infinite.
  • Afterwards you've mounted the LB to the siding, become inside and add together a conduit connector and a metallic electrical box to the other end of the EMT.
  • This box is where you'll make the connections from your house wiring to the new shed wiring.
  • On the inside of the shed, you'll spiral a 4 ten 4-in. foursquare metal box to the side of the stud.
  • Then connect the LB to the box using the parts shown in Effigy B (below).

Footstep iv

Figure B: Through-the-Wall Parts

  • Running the conduit through the wall to an within box is the most hard step.
  • The 10-pes lengths of RMC are threaded on both ends and include a coupling on one end.
  • You'll offset by angle the first pipe and threading an LB onto the cease.
  • So thread the pipes together one at a time until you reach the other terminate, where you'll cutting and bend the last piece of conduit to fit and connect it to the LB with a pinch connector. The photos below evidence the process.

Figure B: Through-the-Wall Parts

Step 5

Run the Metal Conduit and Program the Bend

  • Temporarily attach the LB to the shed and measure from the bottom of the trench to the bottom of the LB fitting.
  • Add 3/4-in. for the threads that'll go into the LB and subtract the angle assart listed on your bender (usually half dozen inches) from this measurement for the bend.
  • Mark this length on a piece of conduit, measuring from the end with blank threads.

Plan the bend

Step 6

Bend the Conduit

  • Pull back on the conduit bender until the end stands directly up.
  • A magnetic level lets you know when you've got a perfect ninety-degree bend.
  • Take the bent conduit dorsum to the trench and screw the LB onto the cease.
  • Align the mark on the conduit with the arrow on the bender.

Bend the conduit

Pace 7

Join the Conduit

  • Assemble the conduit run aboveground to make tightening the connections easier.
  • Support the conduit with 2x4s until you lot've connected all simply the last department.
  • Connect lengths of conduit until you accomplish the house.

Join the Conduit

Stride 8

Programme the Last Piece

  • Bend the last piece of conduit up and cut it off to fit into the compression connector.
  • Start by measuring from the last piece of conduit to the house wall.
  • If the LB is held away from the wall by siding, subtract this distance from the measurement.
  • Then add 3/4-in. for the threading and decrease for the curve.
  • Adapt the measurement for the altitude the LB protrudes from the wall.
  • Marker the last piece of conduit, starting from the blank threads.

Plan the last piece

Step 9

Mark and Cutting

  • Agree the bent conduit in place to marking it for cut starting from the bear threads.
  • Since there are no threads on the finish of the pipe, screw a pinch plumbing equipment into the LB and connect the conduit to it.
  • Face the threaded terminate of the conduit when yous make this curve, not the finish with the coupling.
  • Mark the conduit and cut it with a hacksaw.
  • Remove burrs from the inside of the piping by smoothing with a file or by inserting the blank metal handles of pliers into the pipe and twisting.
  • Complete the conduit run by threading on the last piece of conduit.
  • You lot'll accept to lift the previous piece of conduit to create clearance as you spin the bent pipe around.
  • Finally, slip the end of the conduit into the compression connector and tighten the compression nut with a wrench.
  • Wrap a conduit strap around the conduit and screw it to the house to secure the conduit.
  • Likewise press a rope of "duct seal" effectually the pinnacle of the LB to keep water out.

mark conduit

Step 10

Tie the Wire to Fish Record

  • Remove the covers from the LBs and push a fish tape through the conduit.
  • Feed the fish tape through the conduit.
  • Loop the wires through the fish record and wrap them with electrical tape.
  • Besides wrap the hook on the fish record and then it can't snag.
  • Use stranded wire, not solid wire.

Tie the wire to the fish tape

Step 11

Pull the Wires

  • Pull the wires through the conduit.
    • Pro tip: This is a two-person task — y'all need a helper at the other finish to feed the wires into the conduit.
  • You lot'll demand two wires, one white and 1 blackness, for one circuit, or more than if you intend to wire a three-way switch from the house or add more one excursion.
  • Use THWN-ii, fourteen-gauge stranded wire if you become power from a 15-amp circuit, or THWN-2, 12-gauge stranded wire for a 20-amp circuit.
  • Leave enough extra wire on each end to reach the inside metal box plus 12 inches.

Pull the wires

Stride 12

Start with a Switch

  • The NEC requires a means, such as a unmarried-pole switch, to disconnect the power where it enters the shed.
    • Pro tip: The photo below shows how to connect the switch, ground wire and neutral wires.
  • Connect the wires inside the shed to a switch.
  • Run wires from the switch to a GFCI receptacle, and from there to the residual of the outlets or lights in your shed.

Start with a switch

Originally Published: Jan 14, 2021