How To Find The First Receptacle In A Circuit? Step By Step

In a building, there are lots of receptacles; in fact, every room and even outdoors has one. A receptacle is a circuit’s power outlet into which you plug your appliances. A circuit can have many receptacles along its path before its loop completes.

Many receptacles can make it hard to determine which one is the first along a circuit, especially if you want to fix a GFCI or do some electrical remodeling. You may look around, try to trace it from the power source, and end up confused and wondering

How To Find The First Receptacle In A Circuit? Step By Step

The first Receptacle is the first channel through which current from the power source passes to reach other outlets. It is usually closest to the circuit breaker or the breaker panel. To confirm that a receptacle is the first outlet, follow the steps below.

  • Turn off the power source from the breaker panel.
  • Disassemble the Receptacle and disconnect the wires inside. 
  • Turn back the power, and check if other power outlets have current in them.
  • If there is no power in any other receptacle, you have found the first one. 

In this article, you will get a full rundown on every question about receptacles and how to install them properly.

How Do I Add A Receptacle To An Existing Circuit? 

Instead of creating a new Circuit for a receptacle, you can add the Receptacle to an existing one within the property. This tap can only work correctly if the current circuit can carry the load of the appliances you want to use the Receptacle for. Follow the steps below to add a receptacle to an existing circuit.

To add a receptacle to an existing circuit, you will need the following tools; Voltage tester, screwdriver, wire stripper, GFCI, and Receptacle.

Steps To Adding The Receptacle

  • Determine The Circuit To Add The Receptacle: The circuit should be closest to the position you want to use, and the circuit outlet point will likely be in a knockout box attached to a wall.
  • Turn Off The Power: Shut off the power supply to the circuit by turning off your circuit breaker in the breaker box.
  • Power Test: Using a voltage tester, check the circuit to confirm there is no power (critical). Remove the wrapped wires and test all wires and terminals for power. There should be no voltage at all in the circuit.
  • Disassemble The Circuit: Unfasten the screws on the circuit cover and put them out to uncover the wires, then disconnect the circuit wires and bend them sideways apart from each other.
  • Install The Receptacle: Hold up the receptacle and identify the positive and negative outlet slots. Unroll the circuit negative wire and insert it into the Receptacle’s negative slot. Do the same for the positive and ground wires, then screw the wires tight in their terminals.
  • Cover The Knockout Circuit Box: Push the receptacle with the connected wires into the knockout box and tuck the wires neatly to fit properly. Apply a thick layer of sealant along the box’s walls and mount using exterior screws to fix the Receptacle firmly into the knockout box.
  • Install The GFCI: Strip the outer cover of the circuit cable (about 6 inches ), and the black and white insulated wires(about ¾ inches). Connect the ground wires to their respective terminals on the GFCI. And screw neatly.
  • Turn The Power On: Turn back the power on and test the receptacle for current/voltage using the voltage tester. Also, try the reset button in the GFCI.

How Do I Find The Most Upstream Receptacle In A Circuit To Install GFCI?

GFCIs are usually installed in an upstream outlet to protect themselves and the downstream outlets. The most upstream receptacle outlet is always the one closest to the breaker panel, and you can find it by following these steps:

  • Turn off the circuit breaker and note all circuit receptacles without power; you have a list of everything on the circuit path.
  • Go to the outlet nearest to the breaker panel, remove the Receptacle and disconnect the wires.
  • Switchback the breaker for power to come back, and check all the circuit outlets on your list. If there is no power in them, you have discovered the first and most upstream Receptacle.

Note: if there is still power in any outlet, that outlet is upstream of the Receptacle you disconnected. In this circumstance, shut off the breaker, fix back the dismantled Receptacle and try the experiment with the outlet that has power in it. If there is no actual first receptacle, you will need two or more GFCIs.

How To Wire A GFCI At The Beginning Of A Circuit?

How to wire a GFCI can vary with manufacturers, but generally, they follow the same route.

To specifically install a GFCI at the beginning of a circuit to protect the downstream outlets, follow these steps:

  • Turn off the breaker panel to cut off the power supply and test using a circuit tester to confirm the absence of power.
  • Uncover the receptacle plate by unscrewing the outlet and disconnecting the wires from the circuit.
  • Note the power supply wires (LINE) and the downstream wires (LOAD), and the GFCI uses them to protect all downstream outlets and ensure they are working properly. Make sure the wires are entirely separate and not touching each other. Then turn back the circuit breaker for power and test the hot wires/line.
  • Once you have identified the line, turn off the power to avoid an accident.
  • Strip the hot wires (power supply wires) and insert them into the GFCI terminal marked “LINE.” Do the same for the downstream wires and insert them into the GFCI terminal marked “LOAD” and the ground wires into the terminal marked “GROUND.”


  • White wires = Silver screw
  • Black wires = Brass screw
  • Bare wires = Green screw

Lastly, replace the receptacle and screw it back into the box. Turn back the circuit breaker to restore power and test the GFCI by pressing the test button. If the test button turns off all power outlets, it’s working properly. Reset GFCI with the reset button, and voila.

Does GFCI Always Have To Be Positioned At The First Receptacle?

GFCI doesn’t always have to be at the first receptacle. Placing the GFCI at the first Receptacle will always cause a trip in all receptacle outlets whenever something goes wrong with any downstream outlets. However, putting the GFCI first in line will protect all the other outlets downstream.

If there are five outlets in the room, you can install one GFCI to all five receptacles. But that is an expensive method, so people are hesitant to use it. The cheaper and widely used option is to put the GFCI receptacle first in line to protect all the other outlets downstream. This positioning is why many people argue that the GFCI has to be first in line.

Though cheap, it can also be stressful; if there is a ground fault in any of the receptacle outlets downstream, all the outlets will lose power. True, you can restore the power by pressing the ‘RESET’ button. But if the faulty outlet has a severe problem, the GfCI will keep turning off until the fault is found and solved.

GFCI does not show the outlet that caused the fault. So it is easier to locate the blame if there is a GFCI to each outlet, then the faulty outlet will trip only the GFCI attached. There are advantages and disadvantages to putting GFCI, and you have to consider all sides of the coin before making a decision.

Where Are Receptacles Located?

They are preset requirements on locations of receptacles by the NEC. Below is a summarized version of receptacle locations in a building.

Visit NFPA.ORG for the complete code list. 


  • Receptacles should be fixed over countertops, at least one on each side of the sink.
  • Adjacent to the refrigerator, a double receptacle can serve both the fridge and countertop.
  • The countertop spaces under the wall-mounted cabinets


  • Countertop spaces under the built-in vanities.
  • The closest point is a wall where the room divider is attached.
  • The nearest point in the wall where the bar-type counter is attached.


  • Within 36 inches from the basin.
  • Adjacent to the basin too.
  • The outlet should never be within 30 inches of a shower or bathtub.

Laundry Area

  • At least 6 feet within the location of appliances.


  • Any position on the wall.

Receptacles should never be inside a cabinet or vanity. 


Whether installing a new receptacle or a GFCL, ensure to turn off the power source (circuit breaker) before you start to avoid electrocution and death. Note that the closet receptacle to the breaker is usually the first and the most upstream.


Scroll to Top