DIY Home Improvement Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
A few years ago, I ran 12/3 to 2 20A outlets using a shared neutral. I'd like to change these outlets to be GFCI, but was wondering if GFCI would work on a shared neutral, or if I could only install a single one and just cap off the other line.
 

·
Registered
Joined
·
104 Posts
I dont believe GFCIs work on shared neutrals. I ahve tried it and failed.

Maybe a real electrician can chime in though, and offer a solution.
 

·
Registered
Joined
·
9,036 Posts
You can put ground fault circuit interrupter units on a multiwire branch circuit wherever you wish to.

But if you want to continue protection from one GFCI receptacle to additional plain receptacles, you need a separate 2 wire cable off of the load terminals of the GFCI receptacle.
 

·
Registered
Joined
·
104 Posts
Actually, now I remember what I was trying to do was install a GFCI breaker on a shared neutral circuit. <---- This did not work for me.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #6
I've had trouble with GFCI breakers, as well - especially when the actual load is a long ways away. Not sure why... For instance, an outlet on a lamppost 100-feet from the house never worked.

Thanks for the other responses. I'll put two GFCI's at the end of the 12/3 and then run 12/2 to any other outlets beyond that.
 

·
E2 Electrician
Joined
·
5,655 Posts
I've had trouble with GFCI breakers, as well - especially when the actual load is a long ways away. Not sure why... For instance, an outlet on a lamppost 100-feet from the house never worked.
Then you had a neutral to ground short, or another neutral related issue. I can assure you right now, the issue was not with the GFCI breaker.
 

·
Registered
Joined
·
9,036 Posts
For very long runs beyond a ground fault circuit interrupter, induced currents (due to capacitance) between hot and ground could be sufficient to trip the GFCI.
 

·
E2 Electrician
Joined
·
5,655 Posts
For very long runs beyond a ground fault circuit interrupter, induced currents (due to capacitance) between hot and ground could be sufficient to trip the GFCI.
Not that I don't agree with you... But seriously. You want to give me the exact length that this occurs at? The reason I bring it up, is because I've never witnessed this in the field... I use a meggar and always find an insulation break down.
 

·
Electrical Contractor
Joined
·
3,368 Posts
I've seen it.

We did a pool installation with a rather long feeder conduit. Instead of using several GFCI breakers, we installed a big one on the feeder, protecting the entire pool panel from the source.

Nuisance tripping occurred, even with all the loads turned off.

This was a new installation, with THWN wires installed in PVC conduit.

Ended up having to scrap the idea of Ground-fault protection on the feeder, and used individual breakers on each piece of equipment.

Never had another problem after that.
 

·
Registered
Joined
·
9,036 Posts
If you put the single large GFCI unit out at the pool house rather than at/in the main panel then I would not expect nuisance tripping.
 

·
Electrical Contractor
Joined
·
3,368 Posts
There was no "pool house" -- DUH ...

Besides, you can NOT back-feed a GFCI breaker and use it as a main in a panel
 
1 - 12 of 12 Posts
Top