GFCI Fuese

[Sam E]

[snip]

True.

Also, I remember someone thinking that such a GFCI world CREATE a ground connection. Of course it doesn't.

[Bill]

I see. I didn't understand the significance of "properly installed"--but I get it now (the wording is probably related to "proper subset" in mathematics). Thanks!

Bill

[FromTheRafters]

The same still applies. The proper fuse should be selected for whatever application.

[clare]

NitPicker. In order to provide downstream protection, they need to be "properly installed" - which means installed as I described.

Agaiun, nitpicker. It IS connected to the panel - one way or another. The "downstream" side is the side NOT connected to the panel in any way if the GFCI device is removed.

Upstream = panel side = LIVE Downstrream = load = DEAD

[James Wilkinson]

Yes, sorry, I was more replying to the previous poster.

[DerbyDad03]

So, just to be clear, are you saying that a GFCI with the downstream receptacles connected to the line side is *not* properly installed?

I already said that that was a nit, in fact it's still there at the bottom of this post.

In any case, thank you for affirmation.

Unless to downstream receptacles were wired nutted to the source wires and then pigtailed to the line side of the GFCI. I think that that would be a "proper installation" but I'd not be upset if I found out that it was not.

[Diesel]

Umm. Unless you know something about GFCI that I don't, it's never needed a ground wire. From what I understand, the GFCI is watching the voltage from hot to neutral and if they become imbalanced, it trips.

[Diesel]

Sort of. It's measuring hot and neutral (for a leak, basically). When it sees they aren't in sync (within tolerance), it trips.

[hrhofmann]

se-902203-.htm

The GFCI looks for equal currents in the hot and neutral conductors, using a transformer with both windings connected. A third winding will have an o utput if the (other) two currents are not equal. This is why a GFCI will s ometimes trip on "noise", because while equal the two currents are at 60 Hz , there is noise" at some higher frequency that is not equal on both conduc tors.

[clare]

It is not "properly ninstalled" to provide downstream protection if the downstream is not connected to the load side.

The OP was confused about whether a CGCI outlet protected the outletsm downstream, and I said it did if it was properly installed - OBVIOUSLY meaning properly installed to do the required job of protecting the downstream circuits.

To those of us who understand these things, yes. To those who don't have a clue, perhaps not.

[clare]

And read the instructions that come with that same unit -

Can I use a GFCI in a 2 wire (ungrounded) circuit? Yes. Section 406.3(D)(3) of the 2008 National Electric Code permits a non-grounding type receptacle to be replaced with a grounding type receptacle without a grounding connection. However, the grounding receptacle must be GFCI-protected. The diagram below shows a typical non-grounding (2-prong) receptacle replaced with a GFCI. The GFCI must be marked, "No Equipment Ground." The GFCI can feed through to a grounding receptacle, which must be marked "GFCI Protected. No Equipment Ground." For increased electrical safety, Leviton strongly recommends installing a GFCI in every non-grounding circuit. A ground wire provides protection by offering a parallel path back to ground for any fault current. Without a ground wire, fault current will try and take other paths to ground and a GFCI will trip and cut power under these hazardous conditions. Ground faults are more likely to occur in non-grounding circuits and a GFCI will help protect family members from this potentially hazardous condition

[DerbyDad03]

The difference between you and I in regards to both of these issues is that I see your explanations being more fitting for someone in the know, while you (I think) think that they are geared more for the novice.

Allow me to explain just you know where I'm coming from.

When I hear "properly installed GFCI" I immediately think "properly installed for what purpose"? Properly installed to provide downstream protection or properly installed to protect only itself even though there are downstream fixtures? When discussing this with someone who has no idea how a GFCI works and/or how it can be used, I feel that we would be doing them a disservice if we give the impression that using a GFCI to provide downstream protection is the only "proper" way to install one. That is why I nitpicked your use of the words "properly installed." It wasn't a slam on you, it was a teaching moment for the novices.

The same (IMO) holds for the use of the words "connected to the panel". Yes, those of us familiar with electrical wiring and specifically GFCI's know that it all eventually ends up back at the panel, but once again I feel that we need to be perfectly clear for those that have less experience. If they don't know how a GFCI works, then they may take the words "connected to the panel with the line screws" literally. In other words, if they don't know how a GFCI works, they may think that it needs to be first device in a branch circuit since the words used were "connected to the panel".

Again, all I was doing was clarifying both issues, even it was picking a nit. What may be a nit to us could save a novice both confusion and extra work.

[Diesel]

:) Yes, it has a place to connect ground, so that it can provide a ground to anything plugged into it as well as attached on the load side of it (as long as you ground them too). It doesn't use ground to do it's job and try to prevent you from getting a potentially nasty shock, though. It's monitoring the hot and neutral wires coming into it.

If it sees any difference in current between the two, it'll trip. Faster than a breaker normally can. And under conditions where the breaker might not trip. IE: you're the source to ground, but, you aren't causing enough of a drain to overload the breaker running the circuit and you aren't causing a short circuit condition, either. So, if you can't get free, you're getting cooked.

GFCI won't allow that to happen. It sees the current going back to neutral isn't matching what's coming in on the hot line. A leak has been detected. Cut power, as in yesterday. Saved your ass. You probably didn't even get a tingle, it responds that fast.

Sadly, the GFCI is a little on the sensitive side and can result in unwanted tripping when certain devices try to power up plugged into one. It's not due to a surge on startup of the device.. It's because the device is leaking a little more current than the GFCI is okay with. This leak may still be harmless to you, but, the GFCI isn't okay with it.

If this happens, and the device works fine on other properly wired outlets, you can try plugging a surge (protector) surpressor into the gfci and your device (like a treadmill) into the surge surpressor. This may be enough to stop it. If that doesn't work, an isolation transformer will do the trick.

Also! I've noticed that some surge surpressors will also trip a GFCI receptacle. I suspect it's because a small amount of current is leaking due to worn/cheap MOVs. If yours is, either replace it or try to find a GFCI outlet that you can still make use of that doesn't trip when you try to use it. Tolerance varies, slightly.

[clare]

If installing a GFCI outlet instead of a GFI breaker it will be for 1 of 3 reasons. Number 1 - lower cost to provide complete circuit protection - On my QO panel installation a GFCI outlet is about half the cost of a breaker. I used GFCI breakers even though the cost was higher on the circuits that were not covered by item #3 to follow.

#2 - installing GFCI protection on a fused panel - no other reasonable way to do it. Again - protecting the entire circuit. (sometimes done at the panel - running the wires from the panel to a "deadhead" gfci device - but using a normal GFCI outlet in place of the "deadhead" is cheaper and they are more readily available)

#3 = protecting one or more outlet on a circuit where you do not want the rest of the circuit protected. An example is one circuit feeds powder-room receptacele, refrigerator, and outdoor weatherproof - in that order. The powder-room and weatherproof require GFCI protection - while it is preferred NOT to have a GFCI on the fridge.. This is the only situation where NOT using the feedthrough would be "properly installed"

[DerbyDad03]

So, it sounds like your #3 has you and I in agreement. #3 is all that I was trying to say from the get-go: "Properly installed" with one or more downstream receptacles on the *line* side of the GFCI.

[clare]

Whatever

[trader_4]

While you're at it, might as well correct Clare that there are more than his 3 reasons for installing a GFCI outlet instead of a breaker. I think one big reason he left out is for convenience. Put a GFCI in the bathroom or kitchen and if it trips you can reset it right there, without a trip to the breaker.

[DerbyDad03]

It's not worth it. Just when I thought that we had come to an agreement, he responds with an adolescent "whatever".

Moving on.

[Arnie Goetchius]

Reason number 4: If the circuit uses aluminum wire, the only alternative is a breaker since they don't make GFCI outlets which are rated for aluminum.

[Mark Lloyd]

[snip]

Around 1995 I installed GFCI (no ground wire to or from the GFCI) for my grandmother to use on holiday lights she put on the ground. It tripped after a rain when some fire ants built a mound around one of the lights (unintentional path to ground through wet soil).