I would like to replace a two prong outlet in the kitchen of my 1950's home with a GFCI outlet. The conductor is two-wire (no ground). Will a GFCI outlet work (will I be able to "reset" it)without replacing the wiring?
Is the house wired with Romex (armored cable)? If so that is your ground so the screws holding it to the box will give you the ground or you could run an extra wire from the box to the ground terminal. Also check to make sure you have 110 volts from hot to the box and nothing from neutral to the box this will confirm that you do have a ground just not a separate one like modern wiring.
I would say a GFCI is adding an order of magnitude more protection than a ground ever would. A GFCI will trip on any ground fault, whether it's to the ground of the outlet or another path to ground, like a water pipe or standing in a pool of water while sticking a fork in the outlet.
A ground is some additional protection, mainly if the GFCI failed to work and a connected appliance had a grounding cord.
Yes, it will work fine and do the shock protection job as intended, and test or reset without problems.
When you buy a new GFCI outlet it will come with a stick-on label saying "Ground Not Connected" which you should place on the outlet plate for that receptical.
I haven't yet learned just why that notice is needed, but I suppose there's a valid reason. It's hard to imagine why someone would want to use the ground pin of a receptical to ground something that's not being powered by that same receptical, maybe someone here will explain that part.
It doesn't have to be something else. It could be an appliance with a
3-prong cord. Some people will see a 3-hole receptacle (as GFCIs are) and think there's a ground there. If there's no ground (and a GFCI in no way CREATES one), it's somewhat safer to have that fact indicated.
if a ground wasnt better than a GFCI grounds wouldnt be required, and GFCIs do fail, I found a bad one and replaced it, after testing it with one of those plug in testers, it didnt trip.
Just a side-note, if you have a GFCI without a ground, some testers won't work even if the GFCI is perfectly good.
Why?
Because they test the GFCI by leaking current to ground, but the ground pin isn't connected to a ground, so the tester does not create a ground fault.
That's one reason you should have the "no equipment ground" sticker on ungrounded GFCIs. It's also there for equipment that expects a ground, like electronics, or a tool with a grounded housing for protection.
You can still get a nasty shock from an ungrounded GFCI protected circuit if all the current leaking into your body through a hotwire fault goes back into the neutral wire. This is not uncommon, and is as easy as gripping the metal prongs of an outlet when inserting or removing a plug from a socket.
GFCI's protect by sensing an imbalance between the hot and neutral wires and tripping OFF when this get to be 5 ma. or greater. During the type of fault described above, there is no imbalance and therefore no protection from this type of shock.
As stated by other posters, a ground wire is not required, but if you want to be protected, you hope that the fault leakage will find a path to ground through a cold water piper, damp basement floor, moist earth, etc.
Before the GFCI's were invented, electrical safety was predicated on a good ground being connected to the metal frame of a motor, for example.
Under such circumstances, a hot-to-frame fault would normally result in a near short circuit and hopefully trip the breaker or blow the fuse serving the motor.
GFCI's augment, but do not completely replace the protection that a good grounding system offers.
There is no way that a ground is better than a GFCI. Given the choice of one or the other, I would take the GFCI in a minute. Most of the items one plugs in today don't even have a ground wire, whether it's a hair dryer, toaster, or electric drill. Get any of those wet or with an exposed conductor and grab it while grounded and it can kill you whether it's plugged into a grounded outlet or not. But if it's plugged into a GFCI, it will trip at 5ma in a fraction of a second, whether the appliance has a ground or not, which is much less than the current required to kill you.
Sure, GFCI's can fail. But so can grounds. Haven't we seen plenty of posts on here of folks with all kinds of situations with missing grounds? All you need for a ground to be ineffective is an interruption in the daisy chain of wiring. So, without actual data, I would not conclude that grounds are any more or less reliable than a GFCI.
Since I think I was the first poster on this thread to remind the OP to apply that "No Ground Connection" sticker, I wasn't against it, just pondering about the average citizen not even understand what it means. Well, maybe a techie or perhaps someone trying to test the GFCI with an artificially created external leak to the ground pin hole. When GFCIs first began to appearI once stuck the leads of a 10K one watt carbon resistor between the hot and ground pins on a GFCI to "test" its tripping.
I'm sure that the manufacturers of GFCI outlets are more than willing to include that sticker to maximize their CYA potential.
And I'd agree that a belt and suspenders approach, with a properly grounded GFCI would have advantages over an ungrounded one in unlikely and arcane situations.
Ahh all TWO prong devices today with ANY exposed outside conductive surfaces are DOUBLE INSULATED with 2 layers of protection between conductor and shell.
GFCI with ground is safer, lets imagine your drilling a hole in a wall and happen to hit a active conductor. the GFCI wouldnt know your getting shocked, whilew a ground will.
if you ask me all electric drills should be 3 prong for this reason.
lazy dont want to open walls, basically make do decision that does NOT address the larger issues with the fire risk of K&T the most common ungrounded cause
Not the only one. My house is too new for K&T (built around 1969), but there are still no ground wires (except to laundry area). I do have several GFCIs in use.
BTW, that includes the one that had to be replaces because it was full of ants (eggs and feces too).
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