Installing A GFCI Outlet

How To Attach GFCI Outlets Or Receptacles To A Main Electrical PanelDo you have a question about a GFCI outlet installation? You can consult with our in-office electrician in Mesa AZ free of charge. Voted best electrician Mesa AZ and having over 30 years of experience, he will answer all of your questions about installing GFCI outlets, wiring a GFCI outlet or replacing a GFCI outlet. Our in-office electricians in Mesa are available to assist you today, Wednesday, May 27th, 2020, between 8:00 AM and 5:00 PM. Give them a call today, you will be happy you did.

Consult With Our In-Office Electrician

How To Install A New GFCI Outlet

Before getting started there are two important things to take into consideration.

First, what do you plan on using the outlet for? Having a reasonably good idea of what you are planning on plugging in will tell you how much power will be required. Knowing how much power you anticipate needing will determine if an existing circuit can be tapped into or if a new circuit will be required from your panel. A 15 amp circuit has 1800 total watts of power available and a 20 amp circuit has 2400 total watts of power available. Remember to account for the power demand of existing devices utilizing the same circuit if you are thinking about tapping into an existing circuit.

Second, will the outlet be used inside or outside? Exterior GFCI outlets will need weather proof covers in all cases and exterior rated electrical boxes are required if the box is surface mounted, opposed to being recessed in a wall.

How to Install a GFCI Outlet Outside With a Dedicated Circuit

Utilizing a dedicated circuit is the best method of installing an outside GFCI outlet because it completely separates the new exterior power from the existing interior power. The advantage is that if something outside becomes wet and trips the GFCI or the circuit breaker, it will not affect the outlets inside your home.

The easiest and most cost effective way to do this is to mount the outlet directly on the side of your circuit breaker box as shown in the image above. Outlets can be located up high or down low depending on your needs. It works great for Christmas lights, landscape lighting and watering time clocks.

How to put the outlet into the electrical box and attach a weatherproof cover

Tools Needed

  • Battery powered drill
  • 13/64 metal drill bit
  • 7/8 inch hole saw
  • Channel lock pliers
  • Slotted screwdriver
  • Phillips head screwdriver
  • Wire strippers
  • Voltage tester

Materials Needed

*Note: For dedicated GFCI outlets in other locations it is best to contact our electricians because electrical conduit will be needed and in some cases wiring will need to be added through your attic.

Step 1: Turn off the main circuit breaker in the panel
  • This should shut off all of the power in the panel after the main circuit breaker. Keep in mind that the power before the main circuit breaker is still live and can only be shut off by the electrical utility company.
  • Note: Homes with solar power will have an additional circuit breaker that needs to be shut off to disconnect the electricity. The wires attached to this circuit breaker will still be energized even after the circuit breaker is turned off.
  • If you have an older home and no main circuit breaker is present, it is best to call our local Mesa electricians to do the job for you. Most older panels have very limited space and moving around older (sometimes frail) wires will almost certainly be required.
Step 2: Remove the interior panel cover
  • This is the cover located behind the outer door of the panel, it will have the circuit breaker labels on it. Before removing it make sure there is an empty space for a new circuit breaker. If an empty space is not available it is best to call an electrician because some re-wiring will be required inside the panel to make space for the new circuit breaker. When this cover is removed all of the panel wiring and circuit breakers will be exposed.
Step 3: Confirm the power is off with voltage tester
  • This is the most important step in our “How to Install GFCI Outlets” instructions.
  • Take a reading between both buss bars and also between each individual buss bar and ground. If any electrical power is detected, your main circuit breaker or solar panel circuit breaker is either still on or it is not shutting off properly.
  • If you cannot absolutely verify that your power is off or simply do not know how to verify it for safety, contact our Mesa AZ electricians for help. Serious electrical injury can happen if the power is not shut off.
Step 4: Screw the mounting lugs to new outlet box and fill unused holes
  • The mounting lugs screw into the back of the box in the corners. They are designed to mount the box without compromising the water tight seal of the box. Attaching them kiddy-corner from each other in a vertical position will make mounting easier.
  • Start, but do not completely tighten the grounding screw that goes inside of the box.
  • Plug up all unused holes with the screw-in fillers. Only the back hole should be left open at this point.
Step 5: Mark and drill the hole for the 1/2 inch chase nipple
  • Hold the new box where you want to position it on the outside of the circuit breaker box and mark the back hole and two mounting holes. Make sure all holes are back far enough to clear the interior cover and that the neutral bar is not in the way. Also, gently bend any wires that could get damaged while drilling away from the area. Drilling should be done on the outside of the panel only, never from the inside.
  • Using a 7/8 inch hole saw drill the center back hole for the 1/2 inch chase nipple.
  • Drill the 2 holes for the 10-24 mounting screws using a 13/64 inch metal drill bit.
Step 6: Insert the chase nipple and mount the exterior outlet box
  • Remove any sharp metal remaining attached to the drilled 7/8 inch hole and insert the chase nipple through the panel, screwing it into the new box. Do not tighten it all the way, the mounting screws still need to be lined-up with the holes. Be careful, the metal around the hole will be sharp and very hot after drilling it.
  • Insert and tighten the 10-24 mounting screws (with lock washers and nuts) and finish tightening the chase nipple.

Note: When tightening these mounting screws, leave the slots of the screws in a vertical (up and down) position. This will allow any moisture to run through the slot and help prevent rusting.

Step 7: Continue installing the outlet and weatherproof cover
  • Take your black, white and green wire and from the inside of the panel push them through the chase nipple leaving enough wire hanging out of the new box to attach the outlet.
  • Strip the ends of the wires and attach them to the GFCI outlet using the terminals marked line on the receptacle. See our page about how to wire a GFCI outlet for more details.
  • On the green wire, measure about 6 inches from the outlet and with a knife strip about 1 inch of insulation off and wrap it around the grounding screw inside of the new box. Tighten the grounding screw to secure the ground wire.
  • Gently fold the wires into the box and mount the GFCI outlet by screwing it into the box.
  • Attach the weatherproof cover.
Step 8: Insert the circuit breaker and attach the wires
  • Install the circuit breaker into an unused space and cut the black wire leaving enough to attach it to the circuit breaker. Strip the end of the black wire and attach it to the circuit breaker.
  • Cut the white and green wires, again leaving enough to attach them to the ground and neutral bars. Connect the white wire to the neutral bar and the green wire to the grounding bar. In some panels the ground and neutral bar will be the same bar.
Step 9: Put the interior panel cover back on and turn the power on
  • Remove the circuit breaker knock out from the cover where the new circuit breaker will be and put the interior cover back on.
  • Label the new space on the cover so you will know what that circuit breaker is for and how to reset the circuit breaker for new GFCI outlet if you need to.
  • Turn all circuit breakers back on.

Note: If a circuit breaker will not reset check to make sure that no wires were damage while drilling and that the new wiring is connected properly.

Step 10: Verify that your GFCI outlets are working properly
  • Push the reset button on the outlet to energize it but before using it push the test button to confirm that it is functioning correctly. Push the reset button again and you are finished.
Thumbs UpThumbs Down
How Did We Do?
Learn about wiring a GFCI outlet Learn about replacing GFCI outlets Learn how to troubleshoot a GFCI outlet not working Where are GFCI outlets required

Dolce Electric Company has scheduled in-office electricians Mesa AZ homeowners and businesses can call and consult with free of charge today, Wednesday, May 27th, 2020, from 7:00 AM until 5:00 PM. They can assist you with the installation of your GFCI outlet or any other electrical questions you may have.

Inquire By Email Consult With Our In-Office Electrician Return To Residential Services


Visit Us
Follow Me