Electrical Wiring in the Home/Shared Neutral


Hi Mr Cook,

I am remodeling a bathroom and have found that there is a 14/3 wire supplying two circuits to the bathroom.  One circuit goes to the GFCI, one outlet, 2 can lights located over the tub and the vent fan in the shower area.  The other circuit supplies 4 sconces, an overhead light, a light/fan in the water closet and a small accent light in a built in.  They share the neutral.  The problem is that with this shared neutral, the GFCI will not turn on.  I know they trip because of an imbalance in the hot and neutral but how can I stop that nuisance tripping?  Also, I am concerned that this neutral is overloaded and dangerous to have in place.  Is my only option running a separate line back to the panel?  I was hoping to avoid cutting holes in my walls but I also do not want to burn my house down.  There is also a 12/2 circuit on that same wall for a 120V floor heating system but I want to keep that in place if at all possible.  What are my options here?  Thanks for your time.

I actually do not see how this passed an electrical inspection. The electrical code requires at least one 20 amp circuit per bathroom with no other outlets. As well as this requirement, every electrician knows a GFI will not work with a shared neutral. At this point your only alternative is to run a new circuit without a shared neutral in order to have GFI protection. I wish there was an alternative, but I do not see one. Thanks J
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Electrical Wiring in the Home

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J Cook


General electrical wiring, including but not limited to, residential, panelboards, control wiring, low voltage wiring, Heating and A/C control wiring, single and three phase wiring.


I have been doing electrical since high school. I have been licensed by the State of North Carolina for ten years and am currently the Building Maintenance Superintendent for a municipality. I have extensive control wiring experience.

Refrigeration Service Engineers Society.

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