GFCI's on multi wire branch circuits

As long as the common neutral is only connected to their supply or line terminals they will work fine. Any attempt to supply a multi wire branch circuit from the load terminals of two GFCI receptacles will cause repeated nuisance tripping.

If for some reason you need to supply a multi wire branch circuit through a single GFCI then you must check with you breaker panel's manufacturer and see if they manufacture a two pole and neutral GFCI in the amperage of your existing multi wire branch circuit. There is a Ground Fault Detector that provides dry terminal contacts that could be used to control a shunt trip breaker but at that point it would probably be more cost effective to just install individual GFCI receptacle at all of the outlets to be protected.

-- Tom H

So are you saying that I can't run any other outlets off the load terminals of either/both of the gfci's in this setup??

The panel is a Square D NF with powerlink G3's and I don't think they make any GFCI breakers for it...

|> >

|> > Thanks |>

|> As long as the common neutral is only connected to their supply or line |> terminals they will work fine. Any attempt to supply a multi wire |> branch circuit from the load terminals of two GFCI receptacles will |> cause repeated nuisance tripping. | | So are you saying that I can't run any other outlets off the load terminals | of either/both of the gfci's in this setup??

You can run additional outlets via the load terminals, provided that from those terminals the neutral forever remain separate. You would connect the supply line shared neutral to both linde side neutral terminals. But the load side of the GFCI must not having any sharing going on that can result in a parallel path through both GFCI devices (or through anything else for that matter). Everything that comes through the hot wire on a GFCI must return back via the neutral wire on the very same GFCI.

|> If for some reason you need to supply a multi wire branch circuit |> through a single GFCI then you must check with you breaker panel's |> manufacturer and see if they manufacture a two pole and neutral GFCI in |> the amperage of your existing multi wire branch circuit. There is a |> Ground Fault Detector that provides dry terminal contacts that could be |> used to control a shunt trip breaker but at that point it would probably |> be more cost effective to just install individual GFCI receptacle at all |> of the outlets to be protected. | | The panel is a Square D NF with powerlink G3's and I don't think they make | any GFCI breakers for it...

There are no GFCIs for NF. There is no Powerlink for QO. Do you really needs for these particular circuits to be Powerlink controlled? If not, then an NQOD subpanel fed from a larger EDB breaker in the NF panel could be the way to go (I'm assuming you're not putting 277 on GFCI receptacles).

You can extend the circuit, using only one of the hots and protect everything downstream with a GFCI at the beginning of the new wiring.

Same as above using both hots, except you need to use 2 whites (neutral), one for each hot, and 2 GFCI's. The two whites are connected to the white at point where you connect to the existing multi-wire branch.

If you do not extend the circuit or re-wire it, then you cannot protect downstream receptacles by wiring to the load terminals of a GFCI receptacle.

Ed

|>>>Can I run 2 gfci receptacles (one on each hot and share the grounded) |> |> on a |> |>>>multi wire branch circuit? Or will they trip ? |>>>

|>>>

|>>>Thanks |>>

|>>As long as the common neutral is only connected to their supply or line |>>terminals they will work fine. Any attempt to supply a multi wire |>>branch circuit from the load terminals of two GFCI receptacles will |>>cause repeated nuisance tripping. |> |> |> So are you saying that I can't run any other outlets off the load terminals |> of either/both of the gfci's in this setup?? |> |> | | You can extend the circuit, using only one of the hots | and protect everything downstream with a GFCI at the | beginning of the new wiring. | | Same as above using both hots, except you need to | use 2 whites (neutral), one for each hot, and 2 GFCI's. | The two whites are connected to the white at point | where you connect to the existing multi-wire branch.

And don't get the 2 neutrals mixed up. They must be paired with the hot that goes through the same GFCI.

The connection between the 2 GFCI's and the origination of the circuit at it's 2-pole overcurrent protective device can be a shared neutral.

| If you do not extend the circuit or re-wire it, | then you cannot protect downstream receptacles | by wiring to the load terminals of a GFCI receptacle.

The alternative is to make every receptacle be a separate GFCI connected only on its line side.