I have some 2-wire ungrounded outlets in a room that I want to put a bunch of electronics and computer. I know I can replace this with a GFCI outlet and label with "No equipment ground". What happens to the ground prong with all the stuff that I'm going to plug in aka. all the shields on the equipment, is all of that going to be floating or does that internally (to the GFCI) connect to the neutral wire? Is this a perfectly acceptable solution in this case or are there some dangers / disadvantages that I should be aware of? Many thanks for any help!
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1What type of wiring do you have, NM cable, metal conduit? Can you add a ground to those outlets?– JACKJan 4, 2021 at 15:27
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@MonkeyZeus They could also install a GFCI breaker in the panel as well, or (I think) combo GFCI/AFCI breakers, but that gets expensive. It also depends on what's on the circuit; if the builder/wiring technician opted for cost savings rather than owner convenience you could have a bathroom and a bedroom or two all on the same circuit, so an AFCI breaker would not be sufficient there.– TylerHJan 4, 2021 at 15:52
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1Adding GFCI to an ungrounded circuit does not create a ground - it only adds Ground Fault protection. The ground wires from appliances connected to this circuit will remain floating as they were before. So if you want or need a 'real' ground (EMI reduction for example) then it won't help you.– brhansJan 4, 2021 at 16:14
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@MonkeyZeus CAFCI is just an updated replacement for AFCI; a CAFCI breaker does not provide ground fault protection that would be required for a bathroom.– TylerHJan 4, 2021 at 17:19
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2@TylerH I retract my comments. I was thinking of the dual-function CAFCI/GFCI breakers. This would hopefully cover all bases as I don't believe code has anything against overprotecting your electrical.– MonkeyZeusJan 4, 2021 at 17:40
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3 Answers
(NB: I'm not an electrician, just a homeowner who has done some electrical work)
Related: Does a non grounded GFCI meet code?
It is 'perfectly acceptable' in that it is compliant with code (as long as it is properly labeled, as you state). A GFCI if wired correctly should trip if there is a difference between the current coming in and the current going out (between the hot and the neutral, basically).
However, you are right as well that there are dangers/disadvantages to not having a ground wire. The point of ground wires (and requiring them in new construction) is because it is safer both for you and for the equipment you have plugged in.
Without a ground, a lightning strike or other power surge can seriously damage you (if you are touching a plug or outlet when it occurs) or your equipment plugged into any ungrounded receptacle. Ground wires act as an 'escape route' for extra current to travel safely back to the actual ground underneath your home.
Millions of people lived for decades in non-grounded homes and never had issues. But many people have experienced shock or equipment failure due to said lack of ground. It's up to you if the threat of power surge / lightning strike ruining your equipment is an 'acceptable risk' or not.
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Even if most of the people who lived in non-grounded homes never had issues, enough of them must have had issues that grounding became a requirement. The main reason for grounding isn't actually for lightning or power surge protection. It's to protect people when an appliance develops a short between the hot wire and a conductive housing or other exposed metal part. I was shocked a couple of times by touching an old metal fan at my grandmother's house when I was young. Grounding would have prevented it.– mrogJan 4, 2021 at 23:24
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Yes, this. This is also one reason so many hand tools today are 100% plastic and labeled "double insulated" with just a 2 prong cord. But grounding is really inconsistent unfortunately, I'm sitting here staring at 2 Hamilton Beach toasters on the counter which are 100% chromed steel bodies, steel interiors, everything in them is steel except for the mica insulator sheet the heating coils are on, yet both have no ground wire. I've never understood how appliances manage to get away with this. Yet my laptop that is 100% plastic and fed by a 19v power brick has a grounded cord?!?!?!?!? Jan 5, 2021 at 3:17
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@TedMittelstaedt there's a lot in your laptop that isn't plastic, FWIW. The entire battery, and probably 20-30% of the components use various metals (and other materials).– TylerHJan 5, 2021 at 20:24
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@morg Yes that's a good point; things like wet hands flipping a light switch are also protected by grounding -- Re: "enough of them had issues for grounding becoming a requirement" Yes, the "enough" is probably a very, very low number. Codes like this are written in blood as the saying goes: only takes a handful of deaths or a high enough $ figure to say "hey, we shouldn't allow this anymore".– TylerHJan 5, 2021 at 20:25
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Tyler, it is very random as to whether laptop power supplies have an A/C ground prong on their plugs or not. Some do and some do not. I have even seen supplies for the same model, from the same manufacturer, come with grounded and ungrounded AC power plugs. And "double insulated" power tools that do not have a ground prong have plenty of metals in them too. Grounding in the power DISTRIBUTION system isn't the problem here, it's what various manufacturers do that is weird. Jan 6, 2021 at 4:59
The ground is in no way connected with a 2 wire GFCI setup to convert to 3 wire. The GFCI doesn’t use ground itself but it can use it for grounding the yoke if available.
Code allows a separate ground wire to be pulled so if you are really concerned about having things grounded this is a possibility
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I will put in a plug for a AFCI/GFCI combo breaker here. I just replaced a failed GFCI outlet in the kitchen with one of these on the outlet circuit in a QO load panel. Cost of a 20A breaker with pigtail $52 off the shelf at Lowes. Cost of a single 20A Eaton outlet GFCI only at Lowes - $18. The QO breaker went into a panel that already had a Square D GFCI breaker on another circuit that is 13 years old and still going strong. The failed GFCI was 3 years old. At that rate by the time the new breaker is 13 years old I will have gone through $72 in replacing garbage-grade GFCI outlets.
It is crystal clear to me that companies like Eaton know they are selling GFCI outlets for replacement use only and most sales are to homeowners. Commercial contractors are installing either breakers like I did or entire new panels with ALL breakers Combo. I trust Schneider Electric's Square D brand a lot more than Eaton's made-in-YingTau garbage grade brand that is designed to fail every 3 years so the homeowner has to fork over another $18 for a new outlet. Plus since that branch circuit feeds the kitchen and for all I know probably feeds other things like the garbage disposer so now all of that carp is protected plus whatever weird nonsense that some dingus plugs into a kitchen counter outlet is protected, and not just protected from falling into a sink full of water.
You do what you want but for me I will never spend another dime on a GFCI outlet ever again. Any more GFCI outlet failures will get the GFCI outlet replaced with a NORMAL electrical outlet and a combo breaker. And if I get a "nuisance trip" from some appliance then so be it, into the garbage it will go and be replaced by another appliance.
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1One gfci receptacle followed by plain receptacles is simple enough, and in most cases almost as easy as point of use (I have one gfci that also protects the receptacles in the bathroom below it but trips there are even less frequent than in the kitchen). Jan 6, 2021 at 6:16
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1@TedMittelstaedt -- you're going to need to give me an actual Code citation for GFCI receptacles not being usable in new installations Jan 7, 2021 at 0:51
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1Alright let me start over. Code is now requiring both AFCI and GFCI for wet areas so using a GFCI-only outlet is no longer to code for new construction. Code is requiring AFCI for everywhere so a GFCI-only outlet is not permissible ANYWHERE for new construction save noted exceptions (refrigerator, etc.) that don't require ANY protection. I suppose the "outlet-worshippers" could use AFCI/CFGI outlets everywhere if you want to jack the price up. 2 combo outlets exceeds the price of a combo breaker last I checked and most branch circuits have more than 2 outlets. Jan 8, 2021 at 22:04
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2OK. That is a bit different. If you need (code requirement) AFCI + GFCI, you can get the full protection, and as I understand it satisfy all code requirements, by having AFCI at the breaker (as it protects wires + receptacle issues + device issues) and GFCI at the receptacle (as it protects device issues). Also as I understand it, while GFCI can have true "nuisance trips" due to transient problems (e.g., water spilled on a small appliance), AFCI problems are more likely to be due to things that have to be "fixed" and so ease of reset is less of an issue. Jan 10, 2021 at 2:09
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1Older GFCIs used 5ma current for tripping and they had a lot of nuisance trips, newer ones use 33ma trip current and nuisance trips are pretty much a non-issue. But even the 5ma ones don't nuisance trip if there's not a problem. The last nuisance trip I had on a GFCI breaker was one connected to a Cisco 12 port PoE Ethernet switch. It would trip if the switch turned on when other devices were turned on, but not if the other devices were powered up separately. 6 months later one day the motherboard of the switch just fried. I should have replaced it the first day it nuisance tripped. Jan 10, 2021 at 17:16