Save up to 66% on your DIY electrical Wiring Project & get Material Lists, Instructions, Wiring Tips and more


Installing GFCI Receptacles in Existing Kitchen Circuits

January 21, 2007

Q: I have 2 questions regarding gfci’s. Can they be installed on existing 12-2 wire in a kitchen & work correctly? Is there any way to place a gfci on at 10-3 wire at breaker box when the red & black conductors are being used as separate 120 v circuits on the same side of the breaker box and share the same neutral conductor? Thanks

A: Yes, you may install GFCI receptacles on existing 12/2 wire in the kitchen and they will work properly. In fact, I highly recommend doing this if you do not currently have GFCI receptacles in your kitchen.

To do this you need to turn off the breaker to this circuit. Then use either a receptacle tester or a volt-meter to ensure the power is off at your receptacles. After you are 100% certain your power is off, open up every receptacle in your kitchen and disconnect all of the hot (black) wires from every receptacle.

Now comes the DANGEROUS part. Be sure none of the hot wires are touching each other or anything else and turn on your power. Before you do this, be sure to tell anyone else in the house you are going to turn on the power so no one touches these wires and gets hurt. I recommend wearing a pair of leather gloves and go test your wires. You are looking for the power supply or line side of this circuit. This is the only wire that should have power on it. Working with live electricity is extremely dangerous, I recommend hiring a licensed or qualified electrician to do this for you.

After you determined which wire is the power supply, go turn off the power. The receptacle box that has the power supply, is where you will install your GFCI receptacle. The power supply hot and neutral (white) terminate to the “line” side of the GFCI receptacle. The other hot and neutral in this box terminate to the “load” side.

It is very important to terminate the hot and neutral wires from the same cable to the line or load side of this receptacle. If you terminate the power supply hot wire to the line side of the receptacle and the power supply neutral wire to the load side of the receptacle, the GFCI will not work.

Now reconnect the hot wires to the rest of your receptacles and close everything up. Turn on the breaker and go test this circuit. I recommend using a GFCI receptacle tester to ensure the wires are hooked up right. When you press the “trip” button on the GFCI receptacle, the power should turn off to all of your receptacles in your kitchen. Kitchens are supposed to have 2 – circuits to them, so you will need to install a GFCI receptacle in each circuit.

You can’t use a GFCI circuit breaker on circuits with a shared neutral. If you have a receptacle circuit with 10/3 wire, be sure the breaker is only 15 or 20 amps. If this is a 30 amp breaker, it needs to be changed to a 15 or 20 amp. Your receptacles on these circuits are not rated for 30 amps and you risk starting a fire, before the breaker will trip.

GFCI receptacles are also required in all bathrooms, garages, unfinished basements, crawl spaces, laundry areas, utility areas, wet bar sinks and outdoor locations. If you do not have GFCI’s in these locations, I highly recommend installing them.

DIY Electrical Wiring Help from a Master Electrician Do you need assistance with your electrical wiring project? Please visit my DIY Electrical Wiring Help from a Master Electrician page. Where I provide electrical wiring tips, expert electrical advice, answers to your electrical questions and electrical consulting & design services over the phone, via instant messenger or via email.

If you enjoyed this post, make sure you subscribe to my RSS feed or receive updates via email. You can also follow me on Twitter and "LIKE" me on Facebook.

Similar Posts:
Site Sponsor


2 Responses to “Installing GFCI Receptacles in Existing Kitchen Circuits”

  1. John on April 7th, 2008 1:29 pm

    You said ‘You can’t use a GFCI circuit breaker on circuits with a shared neutral. If you have a receptacle circuit with 10/3 wire, be sure the breaker is only 15 or 20 amps.’

    I have a similar situation in my detached garage. There are two 20 amp breakers in my house sending power to the garage along a single Black / Red / White / bare copper cable that is 10 gague. (One breaker makes the black hot, and the other makes the red hot.)

    Can I set up GFCI for at least one of the circuits?

    Then, could I use the non-GFCI for my garage door and lights?

    I plan to use 12/2 with ground for all wiring after the j-box where I will split the incoming power.


  2. Toni Imler on May 24th, 2010 9:57 am

    My husband and I are remodeling our home. He installed lights in the kitchen (4 – track lights) but, when we turn them on, the bulbs become very hot. All four lights are controlled by one off/on switch. What would cause these small bulbs to get so hot ?