Two wire house... again

10 Replies

Just read this:

Sec. 210-7(d)(3) permits any of the following installations when replacing a 2-wire ungrounded receptacle:

(a) Replace it with another 2-wire receptacle;

(b) Replace it with a GFCI-type receptacle and mark the receptacle with the words “No Equipment Ground;” or

(c) Replace it with a grounding-type receptacle protected by a GFCI device (circuit breaker or receptacle). Since the grounding terminals for the receptacles are not grounded, you must mark the receptacles with the words “GFCI Protected” and “No Equipment Ground

What about the face plates if they aren't GFCI's, do they need to be two prong? 

Do you put these "No Equipment Ground" labels on your receptacles?

You're not supposed to put in a 3 prong non-GFCI receptacle if it is 2 wire without a ground.  If it is a GFCI you're supposed to add the no equipment ground sticker.  Another alternative if you need to plug something in is the 2 prong to 3 prong adapters which are only about $0.50 or you could rip off the ground prong from a surge protector.  

Or I guess you can use a 3 prong receptacle if it is protected by a GFCI:

If you use two prong receptacles, no special labeling is required, since there is no ground terminal in the receptacle. 

The labels are required in the case of a GFCI  or a three-prong receptacle protected by a GFCI device because there IS that third terminal on the receptacle, but it does not have the customary connection to ground. So for example, surge protectors that rely on a ground being present become less useful. 

@Brad Smith, It's common in my area to do as you stated and replace non-grounded receps with a GFCI in order to be able to plug 3 wire appliances into them safely. The labels are generally just stuck to the cover plates and that's what inspectors look for if you pull permits.

The GFCIs are fairly expensive, but you only need the GFCI on the first outlet of a circuit. The rest can be normal grounded receptacles, but still need to carry the label. In many cases, it's cheaper and easier than re-wiring.

OK, I was planning on replacing the ones with three prong receptacles with two prong faceplates.  Cheap

Where can I buy the labels for the GFCI's that aren't grounded?

I know a little about wiring,,,enough to know better than back stabbing outllets(expensive BTDT lesson).

When I wire a 3 way switch I better have a diagram in front of me.

That being said back to original post, subject,  how do you wire a gfi outlet into a 2 wire system and make it trip if there is a ground fault issue???  Do you HAVE to string a new bare wire from the box? Or is that just preferable if possible?

I know you can string wire,pull in new wire almost everywhere with alot of patience and time.  Sometimes small access holes need patched in drywall but thats another thread.  Electricians dont like that job much as its too time consuming vs benefit to them.  Which translated to expensive.  Last househe says YOU pull wire,,,I hook up,,,saved 4 to 5 K doing that.  Somebody on the other end would half the time in a hurry

@Brad Smith , the number of prongs is determined by the receptacle, not the faceplate.  

You may be able to buy just the stickers somewhere, but I've never found them.  But when you buy a new GFCI receptacle it comes with numerous stickers that most people just toss out because they don't need them.  You might need to buy several GFCI outlets just to get the stickers.  Or maybe catch an electrician coming out of your local supply house and just ask them if they have any in their van.

Good luck!  

Originally posted by @Don Meinke :


That being said back to original post, subject,  how do you wire a gfi outlet into a 2 wire system and make it trip if there is a ground fault issue???  Do you HAVE to string a new bare wire from the box? Or is that just preferable if possible?


Ah, you have been exposed to the myth that a GFCI must have a ground wire in order to function as a ground fault protection device. That is a myth. The GFCI functions by sensing the amount of current in the hot and the amount of current in the neutral, and if those two currents do not match to within some small difference a ground fault is "declared" and the device trips - the ground current is not measured, it is assumed to be the difference between hot and neutral currents. As such, GFCIs are allowed by code to be ungrounded if properly labelled as such; appropriate labels are often found inside the packaging with the GFCI. 

And you can test that if you choose by disconnecting temporarily the ground wire from a GFCI and pushing the test button, and it should trip. 

Now, there are GFCI testers that are inserted into a receptacle to test the GFCI; if the GFCI is ungrounded, those testers will not trip the GFCI. Some would conclude from that that the GFCI is not protecting from ground faults, but pressing the test button on the GFCI is the only reliable test method. 

Michael, I've been told by enough sources that rewiring is not necessary so not at this time.  Just trying to make it work as is.

Matt, sorry don't spend enough time responding... I'm going to change whatever needs to be changed.  I haven't taken the 3 prong face plates off to know what's behind them but I will end up with two prong outlets except for kitchen and bath where I'll install GFCI's.

Steve answered the last part... GFCI's sense current differential so don't need an actual ground wire to work although all the electricians I've asked say other wise.  Maybe they have to.

Why would you not leave all the boxes 3 prong and put gfi protection on the few beginning of a run outlets then??  Ever live in a 2 prong house and cant plug anything in unless you go find an adapter? BTDT and its not much fun.

Was thinking the new code calls for gfi everywhere now,,,not just kitch and bath like used to be.

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