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One Methods:Testing GFCI

The National Electrical Code now requires Ground Fault Circuit Interrupter (GFCI) receptacles to meet electrical code in kitchens and bathrooms. This device is installed in areas around water to provide extra protection against electrical shock. This article will tell you how to wire GFCI.



  1. 1
    Turn off the power to the circuit you are working on from your main fuse or breaker box. Unscrew the cover plate with a flat-head or Phillips screwdriver.
  2. 2
    Identify how many cables or wires you have in your electrical box. You should have no more than 4 loose wires or 2 cables with a total of 6 wires between them. Grounding wires are not included in this total.
    • Contact a qualified electrician to complete the work if you have identified more than 4 loose wires or more than 2 cables (grounding wires not included.
  3. 3
    Strip the wires with wire strippers. Connect the white "line" wire to the silver (white) terminal and connect the black "line" wire to the brass "hot" terminal.
  4. 4
    Attach any ground wires to the green grounding screws. Needle-nose pliers may be needed to connect the wires.
  5. 5
    Tuck the wires into the box, ensuring the grounding wire does not touch the other 2 wires.
  6. 6
    Install the receptacle back into the wall.
  7. 7
    Wiring Procedure for 2 Cables (4 to 6 wires)
  8. 8
    Detach 1 white and 1 black "hot" wire from a cable of the GFCI receptacle and put a wire cap on them. Ensure the wires come from the same cable.
  9. 9
    Reinstall the GFCI into the electrical box and restore power at the main fuse or breaker box.
  10. 10
    Plug in a night light to determine if power is flowing into the receptacle. If the power returns, the capped lines are "load" lines, or lines that can be strung together to give GFCI protection to multiple outlets.
    • If no power comes on, your capped lines are the "line" wires or your main power wires.
  11. 11
    Turn the power off at your main panel and take out the GFCI outlet. Label your "line" and "load" wires.
  12. 12
    Attach your "line" white wire to the silver terminal. Attach your "line" black wire to the brass "hot" terminal.
  13. 13
  14. 14
  15. 15
    Attach your ground wires to the green grounding screws. Fold your wires into the box, making sure the grounding wires do not touch the "line" or "load" wires. Reattach the cover plate.

Testing GFCI

  1. 1
    Turn on the power at the main panel and plug in a lamp or night light into the outlet. Press the "Test" button to make the light turn off. The "Reset" button should also pop out.
    • Test the light in the surrounding outlets if you have connected more outlets to the GFCI using the second method. The same result should occur. Press the "Reset" button to restore the power.



  • Never wire a GFCI outlet where an item with a motor, like an appliance, is connected. The momentary electrical surge when a motor starts can cause the breaker to trip. It is fine in a bathroom, since hair dryers and shavers do not draw a lot of current. They should also not be wired where a sump pump is connected, since an accidental trip could knock out the pump.
  • Refer to the instructions that came with your specific GFCI, because the directions can differ slightly from manufacturer to manufacturer.


  • Turn off the electricity to the circuit being worked on to avoid possible electrocution.
  • Do not confuse GFCI receptacles (outlets) with GFCI beakers. GFCI breakers are for main electricity panels and should only be installed by a qualified electrician.
  • Refer to your particular product's troubleshooting guide or contact an electrician if your GFCI test fails.

Things You'll Need

  • Phillips and flat-head screwdrivers
  • Wire strippers
  • Needle-nose pliers
  • Wire connectors (also known as caps)
  • GFCI

Article Info

Categories: Electrical Maintenance

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