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madman
10-23-2014, 07:53 AM
I own a Old Home. There are two rooms that still Have 2 prong wall outlets. There are 3 wall outlets per room. I am concerned for safety and wondered if I can just replace all the wall outlets for new GFCI outlets. Would make in nicer than Yankin of thee ground prong on all the appliances there. Kinda feel like a dentist when I do that hA hA . I gave thought to just changing the main breaker toa GFCI s BUT I would still have the 2 prong outlets which suck as I have to remove the ground pin fro meach appliance I plug In. Yes I di read some Internet advice o nthe GFCI wall outlets, Basically they said so many different things I got scared reading the crap. Anyhow what would be the best course of action? I can NOT rewire these rooms as of yet. Thanx Guys mike

ironmonger
10-23-2014, 08:05 AM
Unless you provide a ground in addition to the hot and neutral at the device location, the GFCI will not function.

Please rewire instead of destroying the ground pin on appliances that have have them.

paul

J Tiers
10-23-2014, 08:08 AM
GFCI s may be used on 2 prong circuits. In fact, ONE GFCI will protect all the outlets "downstream" of itself, that is any outlet having wires that come off the GFCI.

For the US, it was common in the past (not accepted now) to wire from outlet to outlet by connecting incoming wires to one line/neutral pair of the screws on an outlet, and wiring off the second pair to go to more outlets on the circuit. If the incoming wires are connected to the GFCI line connections, and the remaining outlets are connected to the protected side, they are all protected, despite being 2 prong.

I understand the desire to have a ground pin position in the outlet, and simply directly replacing all with GFCIs will allow that.

I am not sure what scary things you saw. So long as the GFCI is an actual working unit, it should be fine. The main issue is products which want a real ground for some functional feature (computer EMI filters, for instance) will not have that, and may not function correctly. But, of course, they would not have functioned with the original 2 prong outlet either.


Unless you provide a ground in addition to the hot and neutral at the device location, the GFCI will not function.

Please rewire instead of destroying the ground pin on appliances that have have them.

paul

This is, of course, NOT TRUE of any properly made GFCI. The residential type GFCI simply opens if the current leaving the outlet on the hot wire, does not all return on the neutral. That does not require an earth connection.

The alternative to clipping off ground pins (cutting pins earns you a whack upside the head with a pipe around here), is to use one of the "3 prong adapters", simply ignoring the 3rd prong connection. It's cheaper than having to put a new plug on the unit later, because you can simply remove the adapter and all is as it was.

I will say that while I have been known to use those adapters, it is not to be regarded as safe or a good plan in general. I simply have many 2 prong outlets, this house is about 80 years old, and it is hard to rewire them all. A bit too new to have been originally "wired for gas", but still far from modern

madman
10-23-2014, 08:20 AM
I actually spent some time reading electrical gfci stuff on the Internet sites and found just a lot of confusion which I am already suffering from in a big way. I have a GFCI outside my House and also a GFCI in my RV. When I ran a extension cord (It was a 10-3 wire cable) to my camper the gfci would trip all the time and eventually it burned out? I had a electrician come and say to me do NOT put two i na row bad Mike!! Anyhow I wanted to put 3 GFCI s in my room and wondered if it would work. I plan on taking a 2 wire tester and seeing if my hot side (small slot) and the screw holding the cover plate on lights up. If it does it is OK and probably has a BX sheathing style gound? (aluminumn strip running inside the BX Wireing.) Im scared of electricity and have had some impressive jolts as a Kid poking around dads old radios! Also it seems the Older outlet boxes seem smaller? Anyhow Thanx Mike

madman
10-23-2014, 08:22 AM
I forgot to mention fro mreading in internet regarding gfci s (dont know whats right or not so much bull on the net and contradictory advice??!!) I read that the gfci can be replaced from the previous 2 prong unit and give human protection fro mshock BUT NOT equipment priotection since the thing doesnt have a ground right?/ Lemme Know thanx Guys Mike

Duffy
10-23-2014, 09:44 AM
Madman, have you opened a box and looked at the wire? Unless it is knob and tube, it is probably old fabric-covered two-wire plus ground stuff. The ground is likely even attached to the box terminal. In the not-too-distant past, the receptical simply was not provided with a ground connection. If you are lucky, the ground is there and you just have to change the receptical and add a ground pigtail.

Fasttrack
10-23-2014, 11:52 AM
I have an old house, too. I just went through this. JT's post is spot-on. You only need one GFCI on a circuit and you can then replace all of the protected 2-prong outlets with 3 prong outlets. This is allowed by the NEC in existing installations as long as you mark these with, "GFCI PROTECTED: NO EQUIPMENT GROUND".



For the US, it was common in the past (not accepted now) to wire from outlet to outlet by connecting incoming wires to one line/neutral pair of the screws on an outlet, and wiring off the second pair to go to more outlets on the circuit. If the incoming wires are connected to the GFCI line connections, and the remaining outlets are connected to the protected side, they are all protected, despite being 2 prong.

...

The residential type GFCI simply opens if the current leaving the outlet on the hot wire, does not all return on the neutral. That does not require an earth connection

ironmonger
10-23-2014, 06:37 PM
Well I'll be...

But see here:
http://www.checkthishouse.com/4661/nec-requirement-for-gfci-without-ground-installation.html
about 5 paragraphs down. It kind of speaks to "just because you can doesn’t mean you should.

I would also suggest a call to your local electrical inspector, as his word means more that anything that any of us might suggest. A call to your home owners insurance rep is also in order. Make sure you would be covered if something like paragraph 5 happens.

When you get to the part where it says "It's going to hurt" I'm thinking that a two wire GFCI is not a very good idea.
Check out Duffy's suggestion.
Or just pull some new wire

paul

J Tiers
10-23-2014, 07:30 PM
NEC, section 406D paragraph 3b, and 3c in the edition I have handy right now.

Allows use of a GFCI, OR a GFCI and 3 prong outlets, to replace 2 prong ungrounded outlets, so long as none of the ground prongs are connected, and the outlets are labeled as "GFCI protected" and "no equipment ground".

As always, the local authority has authority. They can make you connect the ground to the hot wire if they want. But the NEC defines safe construction, and has the force of law where adopted by the local authorities, which is pretty much everywhere in the USA.

As for the "it's going to hurt" comment.... the test button connects a high value resistor from the hot to the device ground. The resistor is picked to allow the smallest "must trip" current to flow, and if you are also in circuit, adding resistance, the current will be less than that. You can be in circuit if the unit is a "no ground" installation.

The current allowed is enough to give you a tingle, yes, but it is limited. The implication of that website is misleading, to say the least, it pretty much implies that you will be connected directly to the hot wire, which is not so.

So, don't use a metal plate on ungrounded outlets... that's not a very good idea anyhow, since you have no clue if a stray wire strand is touching the plate without any GFCI, in which case you would get an unlimited zap.

Having a GFCI is safer than not, since the point of the GFCI is twofold... One, if the unit has a ground wire, and a fault occurs, the GFCI limits the damage, arcing, and fire hazard. Two, if the ground wire is broken or there never was one, and there is a fault, the GFCI reduces your risk of being killed by electric shock.

You are safer WITH it than without it, despite the test button issue.

On the other hand, if you habitually test electrical stuff while standing in water, or holding a water pipe, you may have bigger issues that a GFCI is not the best solution for. :D

If you prefer to replace the outlets with 2 wire outlets and no GFCI, that's allowed also. The quoted items o the website are from the NEC section I called out above

Just because someone on the internet said it, doesn't make it correct, or applicable, or as important as they say. It's a good idea to check the info out. That goes for anything that is said here, as well.

Don Young
10-23-2014, 10:40 PM
At least some GFCI outlets come with a "NO EQUIPMENT GROUND" sticker in the box. Equipment grounds are not needed for shock protection with a GFCI. If the GFCI outlet does not fit easily in the box, use a GFCI breaker. If properly installed as the first outlet in a circuit string, all other outlets on that string can be conventional outlets with the ground hole. All of them should have the "NO EQUIPMENT GROUND" sticker.

darryl
10-23-2014, 10:50 PM
And unless this has already been covered, if you were to simply replace the old outlets with new ones, you'd have the hole for the ground pin and not have to use an adapter. Of course it would be good to wire on the ground if the box has that in it. Now I'm not sure of the legality of this- but if using the adapter is legal, then changing the receptacle should be legal as well. Just my O

J Tiers
10-23-2014, 11:23 PM
And unless this has already been covered, if you were to simply replace the old outlets with new ones, you'd have the hole for the ground pin and not have to use an adapter. Of course it would be good to wire on the ground if the box has that in it. Now I'm not sure of the legality of this- but if using the adapter is legal, then changing the receptacle should be legal as well. Just my O

It's perfectly legal...... IF you have a GFCI as the first outlet in line, and the 3 wire outlets all tagged off the protected side.

The adapters are technically NOT for using 3 wire on a 2 wire circuit by ignoring ground. What they are for is ADDING a ground connection (to the box screw), to produce a grounded outlet where there is not one. They are a groundING adapter, and not a ground LIFTing adaptor.

Naturally that depends on the box being grounded, Either nicely grounded by tight conduit/EMT, or in a doubtful manner by the spiral wrap of ancient BX/armored cable. new BX had the shorting strip in it, and any modern install should use type MC, which has a green ground wire inside the armor.

The other usage, for "lifting" or actually eliminating / ignoring the ground connection, is for barbarians and unwashed heathen such as myself.... Any older electrical engineer or tech has a bunch of them used for test equipment when you can't ground it for some reason of interference etc.

We don't need no steenking rules......