View Full Version : Wiring GFCI with Black, White and Red

Novice in Texas
October 9th, 2007, 08:18 PM
Good evening: I have replaced all receptacles in teh past 3 homes I owned. Recently bought a home built in 1968. I attempted to replace the kitchen receptacles with GFCIs. However, when I pulled the existing receptaclres from their boxes, each contains 2 black, 2 white and 2 red wires. I assume the red are hot like the black, but what are they and how do I wire the line and load of the GFCI?

Thank you for your time.

October 9th, 2007, 09:47 PM
You most likely can't do it with GFCI receptacle. This is most likely a "multiwire branch circuit" which is basically two separate circuits that share a common neutral. These may have been wired "canadian style" where the red is powering say the top receptacle and the black does the lower one.

The only way you can GFCI this is to use a double pole GFCI breaker. Unfortunately, these cost well over $100 each if you can even find one for your panel.

The only solution I can offer is to abandon either the red or black and put a GFCI first on the outlet run. Then, at some point along the counter outlet run, don't daisy chain anymore and run a new circuit to the remaining receptacles. If running a new wire to any of the receptacles is not feasible (you can cut the new feed in at any receptacle), you're stuck with a DP GFCI breaker solution.

October 9th, 2007, 11:43 PM
If you put in gfci's I believe things will work provided you put a gfci at each location and only pigtail the neutral and hot to the line of the gfci...no load connections. Alternate with black to the gfci at one location then pass the red thru and then connect red to the next gfci and so on.

Kind of expensive though.

October 10th, 2007, 07:50 AM
Great solution -- totally forgot about not using the load side of the GFCI! Your solution is still probably cheaper than a double pole GFCI unless he has over 10 receptacles to do.

October 10th, 2007, 08:56 AM
Are you in Canada? It used to be code to require split wired receptacles in the kitchen. It is not a requirement to upgrade these to GFCI. If you do you must change them to 20 amp circuits. The current code requires either split 15 amp or unsplit 20 amp on kitchen counters.

October 10th, 2007, 10:18 AM
With just three outlet boxes you might get away with non-split circuitry, one GFCI serving just the first box using red and pigtailed white, and one other GFCI in the second box using only black and white and also serving the third box if any via its load terminals. Subject to having 12 gauge wires if non-split circuitry at and beyond the first box needs 20 amps.

Since you mentioned the kitchen I might add that it is not good to have the refrigerator on a GFCI protected circuit. Using individual receptacle GFCI's can solve this dilemma.