REDUNDANT GFCI

[kwired]

Neutral to ground faults have tripped GFCI's as long as I can remember. I believe the electronics in older versions (not sure about the new "smart" versions)are connected to the load side so it provides enough load to trigger the ~6ms trip threshold.

That is my recollection as well. If they didn't have neutral - ground detection back then that would have to mean there was still some current flowing anyway that caused them to trip. I can see this happening if you had load upstream on the neutral and there were some neutral to ground voltage, but a cable run to the service panel should have no voltage between those two conductors if there is no load on either one of them.

Now you guys are going to make me find an old GFCI to test.

 

[iwire]

So let me ask you guys which makes more sense.

The manufacturers where including this feature and UL decided they better catch up and change the standard to include it.

OR

UL changed the standard and the manufactures had to comply.


I firmly believe it is the later but in truth ..... who cares.

 

[kwired]

So let me ask you guys which makes more sense.

The manufacturers where including this feature and UL decided they better catch up and change the standard to include it.

OR

UL changed the standard and the manufactures had to comply.


I firmly believe it is the later but in truth ..... who cares.

30 years ago if one manufacturer was doing it, they would chalk it up to product improvements and would have realized they may be higher priced then competition but would put more effort into selling their new feature.

Today if they find an improvement to something, it becomes either code requirement or new listing standard.

 

[curt swartz]

OK........

I have had the opportunity to test several Leviton and P&S GFCI receptacles including 1990's and 2000's era's. I also tested an 1980's SquareD GFCI receptacle for those that have been in the trade long enough to remember them.

All devices had nothing connected to the load terminals or any device plugged into the receptacle. All devices tripped instantly when the load neutral terminal was shorted to ground.

 

[kwired]

OK........

I have had the opportunity to test several Leviton and P&S GFCI receptacles including 1990's and 2000's era's. I also tested an 1980's SquareD GFCI receptacle for those that have been in the trade long enough to remember them.

All devices had nothing connected to the load terminals or any device plugged into the receptacle. All devices tripped instantly when the load neutral terminal was shorted to ground.

So that means they either had neutral - ground detection circuitry or there was enough neutral to ground voltage to make enough current flow to trip them.

I still believe the neutral - ground detection circuitry has been in them longer then some think it has, I think it has been standard since at least the late 1980's