GFCI outlet disconnect neutral too when tripped ?

[Stevenfyeager]

When a gfci receptacle trips, does it disconnect the neutral or just the hot ? It’s an odd question, sorry. Thanks

 

[mopowr steve]

I believe it does, since the last time I had one apart.

 

[Jraef]

I would not have thought so, because It would be potentially dangerous to disconnect the Neutral only, so if the Hot contact welded and only the Neutral contact opened, it could create that situation, ergo it would not be worth the risk. But looking at internal diagrams on line for GFCI receptacles, it does appear that they use a 2 pole N.C. latching relay inside and disconnect both the Hot and Neutral together. I guess they feel confident enough in the relay contacts to both open.

In a GCI breaker, it would only disconnect the Hot, so it can't be a regulatory compliance issue. Makes me wonder why they do it.

 

[Rock86]

Teardown: Leviton ground fault circuit interrupter - Power Electronic Tips

www.powerelectronictips.com

 

[synchro]

I believe a GFCI receptacle will still be operable if the hot and neutral line inputs are reversed because the circuitry does not have or depend on a connection to an EGC, and hence the circuitry would not be able to determine the hot from the neutral. Therefore at least part of the reason for having a 2-pole disconnect on a receptacle may be to make sure the hot can be disconnected even when the line inputs are reversed. Of course for several years GFCIs have incorporated a test to lock it out if the connections to line and load are reversed.

Most typical circuit breakers are not susceptible to line / load reversal and so the neutral would have no need for a disconnect.

A GFCI receptacle can connect a resistor from the line side neutral to the load side hot in order to bypass the CT for testing. Plug-in type GFCI testers don't have access to the line side of the GFCI and so they need to have an EGC for connecting a resistor to create a ground fault current.

 

[jimport]

I have had service calls where the neutral was open until a hidden gfi was reset.

 

[480sparky]

First thing I do when TSing a dead receptacle is to measure resistance between ground and neutral. If there isn't any continuity, I start looking for the tripped GFCI that opens the neutral.

 

[Electromatic]

Every relatively new GFCI receptacle that I've worked with opens the hot and neutral. As others have said, it can be a good troubleshooting technique to look for a GFCI if you have an open hot and open neutral / no continuity from neutral to ground. I'm not sure if older ones -- say 1980s -- opened the neutral or not (if they're still operational at all!).

I did a quick search about GFCI breakers and couldn't find any good info. It does seem that if it were a 2- or 3-pole, it should open the hots and the neutral, or you could have a hazardous "loaded" neutral.

 

[480sparky]

...... I'm not sure if older ones -- say 1980s -- opened the neutral or not (if they're still operational at all!)........

Somewhere I have one of those oldies I upgraded recently. I'll have to find it and test it.