gfi receptacle

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domnic

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Electrical Contractor
Does a GFI receptacle break the hot and the grounded conductor when tripped?
 
090227-2031 EST

Yes. Why?

You can use an ohmmeter or other continuity tester to verify this.

However, there are differences in the logic of different brands in how the trip control and reset work.

.
 
I think they would all have to break both the hot & neutral.

Suppose there's more power going back on the neutral than is going out on the hot? In other words, you're getting shocked from another source of power through the GFIs neutral. If the neutral didn't open, then you still are getting shocked, even if the hot is opened on the GFI.
 
We have examined the internal circuitry of a GFCI receptical both in schematic and via experimental investigations. These confirm that both hot and neutral are opened.
I have not seen a schematic nor disassembled a GFCI circuit breaker.
Does the breaker open both?

Gar,
I do not own a breaker or I would test it.
 
I believe they only open the hot. There is no reason to open the neutral. The only way you ever get shocked off a neutral is if it opens and one side then becomes a hot. If you open the neutral going to a GFI there no longer is a path for current. Yes, current can go out the hot and the GFI will trip as it is not being equaled in the neutral, but opening the hot side solves the problem.
 
Hypothetically if you WERE going to continuity test I would make good and sure to test for V first.......obvious reason, but I've seen a couple forget before....not pretty.
 
iaov said:
I believe they only open the hot. There is no reason to open the neutral. The only way you ever get shocked off a neutral is if it opens and one side then becomes a hot. If you open the neutral going to a GFI there no longer is a path for current. Yes, current can go out the hot and the GFI will trip as it is not being equaled in the neutral, but opening the hot side solves the problem.
Click to expand...

1. Read my post #4.
2. If the neutral is opened, there are plenty of ways for current to flow. That's the reason we have GFIs..... it's because the current is flowing somewhere else.

Think about it.
 
They started out by requiring only the ungrounded conductor to be opened and the neutral was left closed. The requirement was for portable GFCIs to open both since they could be plugged into a mis-wired receptacle. After seeing mis-wired GFCIs, the standard was changed to require both the ungrounded conductor and the neutral to be opened. I don't know when this happened but it was around 1985 ? 5 years or so. :)
 
090228-0929 EST

daleuger:

I would have no expectation that someone would do a continuity check on a GFCI while it was wired in a circuit. When one has a device that they are trying to evaluate what is inside without opening the device the starting point is with that device unattached.

In the case of some, maybe all new, GFCIs power has to be present on the line input to reset the latch. To do these experiments one connects a plug and cord to the GFCI, apply power, set the latch, then remove power and do the measurements.


ELA:

I do not have a breaker type either.


480sparky:

Why on a breaker GFCI is there any need to open the neutral? If this were done it would greatly complicate the breaker for no net advantage. At a breaker panel there is an extremely high probability that the neutral bus is connected to neutral and not to hot. Thus, under normal conditions the voltage between neutral and earth is only a few volts and only results from a current in the neutral. No current no voltage drop.

At a GFCI outlet there is a much greater possibility of incorrect wiring and a reversal of hot and neutral. Thus, double pole seems necessary.

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gar said:
........

480sparky:

Why on a breaker GFCI is there any need to open the neutral? If this were done it would greatly complicate the breaker for no net advantage. At a breaker panel there is an extremely high probability that the neutral bus is connected to neutral and not to hot. Thus, under normal conditions the voltage between neutral and earth is only a few volts and only results from a current in the neutral. No current no voltage drop.

At a GFCI outlet there is a much greater possibility of incorrect wiring and a reversal of hot and neutral. Thus, double pole seems necessary.

.
Click to expand...

GFI breakers and GFI receps are two different critters.

I was speaking about GFI receps as that is what the thread is about. I never mentioned breakers.
 
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