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ElectricalAug 13, 202623 min video

How to install an outdoor 50 amp RV outlet

This covers running a new 50 amp, 240-volt circuit from your panel to a weatherproof NEMA 14-50 outlet on an outside wall, with the cable fished inside the walls the whole way.

Time
About 5½ hours, filming included
Cost
$344 in materials
Pro estimates
Up to $1,400

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Two pages of the Add a 50 Amp RV Outlet at Home guide

Printable guide to this video

Add a 50 Amp RV Outlet at Home

How to check your house can take it, buy the right parts and wire it safely yourself, from a main panel or a sub panel to an outlet on the wall or on a post in the yard.

  • Find your job: main or sub panel, outlet on the wall or on a post in the yard
  • The wire for your run, the breaker for your panel, and what it all costs
  • Wiring the outlet and the panel, with drawings for main and sub panels
  • Testing it before the camper goes on, and fixing what’s not right

Get the guide

Step by step

What you’ll need

  • 6/3 with ground copper NM-B cable (consider 4 AWG on runs over about 100 feet)
  • 50 amp two-pole breaker listed for your panel (GFCI type where your code requires it)
  • 50 amp outdoor RV outlet box (NEMA 14-50R), listed for wet locations
  • Push-in connector for a ¾-inch knockout, rated for 6/3, that installs from inside the panel
  • Torque screwdriver (inch-pounds)
  • Multimeter with a 600 V AC range
  • 50 amp RV surge protector with indicator lights
  • Fish rods and pull rope
  • ¾-inch and 1-inch drill bits
  • Cable cutters for 6 AWG copper
  • Exterior sealant

Before you start

  • Your panel needs two free spaces, and your service needs room for up to 12,000 watts more. Run the NEC 220.83 load calculation; a full panel means adding a subpanel, and an overloaded service means a bigger service first.
  • Check which NEC edition your area enforces and whether you need a permit. Under the 2020 and 2023 NEC this outlet needs GFCI protection outdoors or in a garage, so you’d use a 50 amp two-pole GFCI breaker.
  • Keep the cable inside the house all the way to the back of the box. NM cable isn’t allowed in wet locations, and that includes outdoor conduit, so any outside run needs a wet-rated method such as conduit with 6 AWG THWN-2 wires.

  1. Shut off the power

    A dark garage wall where the open subpanel is barely visible after the power is cut, with an on-screen label reading Power off at main, house main panel.

    Turn off the breaker feeding the panel and confirm it’s dead with your meter. In a main panel, the incoming service wires and their lugs stay live even with the main breaker off.

    Watch this step (2:22)

  2. Fish the cable into the panel

    Looking up inside the top of the open breaker panel at a yellow fish rod coming down through an opening beside other cables, with an on-screen label marking the 3/4-inch knockout.

    Drill a ¾-inch hole through the top plate above the panel, push fish rods down into the panel, then pull a rope back up and feed the cable down while a helper guides it. Knock out a ¾-inch knockout from the inside, slug and ring; 6/3 needs the ¾-inch size.

    Watch this step (2:48)

  3. Run the cable to the outlet spot

    Jeremy kneels outside and drills a hole through the lower siding of the garage wall with a yellow cordless drill, wood shavings on the concrete below.

    Drill a 1-inch hole through the outside wall behind the box’s rear opening, then drill the top plate above it and fish the cable down. 6/3 can’t bend tighter than five times its diameter, about 3 inches (NEC 334.24), so plan the turn into the box; I cut a small piece out of the plywood to clear a stud and get the angle.

    Watch this step (7:42)

  4. Mount the outlet box

    A grey-green outdoor outlet box fastened to the siding between two garage doors, with a thick black cable coming out of the hole in its back and hanging down to the driveway.

    Feed the cable through a connector in the box’s rear opening before you fasten the box, leaving at least 6 inches of free wire. Level and screw the box down, then seal around the hole so water can’t get into the wall.

    Watch this step (9:24)

  5. Wire the outlet

    A hand holds the 50 amp receptacle in front of the open outlet box, with the cable's red, black and white wires attached to its terminals.

    Bare ground to the box’s ground screw and the receptacle’s G (the round slot), white to W (silver), black and red to X and Y (brass). Torque each screw to the number on the receptacle, about 40 to 75 inch-pounds depending on the model.

    Watch this step (10:14)

  6. Bring the cable into the panel

    Seen from behind, Jeremy reaches into the top of the open breaker panel with a gloved hand and pushes a white plastic connector up the black cable toward the knockout.

    Slide the push-in connector onto the cable before you strip it, then snap it into the knockout from inside the panel so its teeth stop the cable pulling back out. Check the package says it can go in from inside; most connectors can’t.

    Watch this step (13:13)

  7. Land the ground and neutral

    An on-screen diagram of the actual subpanel showing where the white neutral, the bare ground and the black and red hot wires land.

    Bare ground to the ground bar, white to the neutral bar; in a subpanel those bars must stay separate (NEC 250.24(A)(5)). With a GFCI breaker, the white goes to the breaker’s neutral terminal and its coiled white pigtail to the neutral bar.

    Watch this step (15:06)

  8. Install the breaker and connect the hots

    A hand presses a new two-pole breaker onto the bus in the open subpanel, with red and black wires running through the panel.

    Snap the two-pole breaker onto the bus, put the black and red wires under the lug clamps (not behind them), and torque to the value on the breaker label. Write the new circuit in the panel directory.

    Watch this step (16:44)

  9. Check it with an RV surge protector

    An RV surge protector plugged into the new outdoor outlet hangs below the box with its row of green indicator lights lit.

    Put the panel cover on, then turn on the power and the new breaker. Plug in the RV surge protector; all green lights means the wiring checks out. Press a GFCI breaker’s test button, then reset it.

    Watch this step (17:59)

  10. Confirm the voltages with a meter

    Hands hold an orange multimeter reading 118 volts with its red and black probes in the slots of the new outlet.

    On 600 V AC you want about 240 volts across X and Y, 120 from each hot to W and to G, and near 0 from W to G (I got 118 hot to ground, 237 across). Zero across X and Y means both hots are on one leg; 240 from a hot to W means a swapped neutral. Either can wreck a camper.

    Watch this step (18:31)

  11. Plug in the camper and close the lid

    Jeremy crouches at the outdoor outlet box and presses its lid down over his camper's yellow-handled plug, which keeps the lid from closing all the way.

    An outlet that stays plugged in outdoors has to be weatherproof with the plug in (NEC 406.9(B)(2)), so check your cord’s plug fits under the lid. My camper’s big-handled plug keeps mine from closing all the way.

    Watch this step (19:36)

Mistakes to avoid

  • Using 8/3 cable on a 50 amp breaker, or a 60 amp breaker on 6/3: NM is held to its 60 °C rating (40 amps for 8 AWG, 55 for 6 AWG), and a single 50 amp outlet can’t sit on a bigger breaker.
  • Using 6/2 or a three-wire hookup: the camper’s 120-volt side needs a real neutral, and the bare ground can’t double as one.
  • Blaming the breaker when the camper trips a GFCI: about 5 milliamps of leakage trips one, and a failing water heater element or a lot of camper electronics can add up to that.