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I just bought a 1955 house with 95% of the outlets 2 prong ungrounded. There seems to be one grounded 3 prong outlet in each room.

I reached out to my electrician for a quote to add grounds to all outlets in the house. He said I could do that or it would be cheaper to just replace the outlets with GFCI.

I can easily change out outlets for GFCI's myself. But I have 4 and 7 year old kids. What would be the safest or recommended action to take? Have an ungrounded GFCI or grounded regular 3 prong outlets?

richie894
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    @Ruskes This is completely wrong. Code specifically allows 2-prong outlets without ground to be replaced with GFCI outlets. In fact, a GFCI can be safer than a grounded 3-prong outlet. – DoxyLover Jun 13 '22 at 00:43
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    Just for fun, you might check and see if those 3 prong outlets are actually grounded. Sometimes they are; you’ll find a bootleg ground; sometimes there’s no ground. – Aloysius Defenestrate Jun 13 '22 at 00:57
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    @DoxyLover you are correct, I was wrong. – Traveler Jun 13 '22 at 00:59
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    Minor fyi: old houses often have small junction boxes that don’t have room for gfci receptacles. One can change boxes, but there might be a lot of work involved. At that point, a gfci breaker swap starts to look cost effective. – Aloysius Defenestrate Jun 13 '22 at 00:59
  • If your electrical panel supports them then get GFCI breakers installed. – MonkeyZeus Jun 13 '22 at 13:23
  • If you're worried about the kids sticking things into the sockets, you can get a pack of those plastic safety plugs for fairly cheap. Not that replacement outlets are that expensive either, but it is a lot more work if you've got a large number of them. – Darrel Hoffman Jun 13 '22 at 17:19
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    I fail to see how you having 2 children age 4 and 7 make any difference as to whether you should have grounded outlets or not. They can still shock themselves either way by sticking something into the receptacle. The only reason you would need grounded outlets is if you have equipment that requires a three-prong plug. They are not otherwise inherently any safer. – Glen Yates Jun 13 '22 at 21:39
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    Follow your electrician's advice over ours, as he/she has seen your house and we have not. – spuck Jun 13 '22 at 22:56
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    "95% of the outlets 2 prong ungrounded. There seems to be one grounded 3 prong outlet in each room." So according to basic math, each room has 20 outlets in total, 19 2 prong and one 3 prong. That's a lot of outlets. – Nobody Jun 14 '22 at 13:54
  • 1955 is a perhaps little early, but many homes were built prior to maybe 1965 with cables that contained a ground wire, even though they used only 2-prong outlets. You should check to see if ground wires are present (and if they are properly connected). – Hot Licks Aug 27 '22 at 18:48

6 Answers6

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The National Electrical Code specifically allows ungrounded 2-prong outlets to be replaced with GFCI outlets or 3-prong outlets protected by upstream GFCI outlets or breakers.

This can actually be safer than a properly grounded 3-prong non-GFCI. For example, if a child pushes a butter knife into the hot prong of a normal outlet, they can be shocked, while a GFCI will prevent any shock. A GFCI functions by comparing the current flow between the hot and the neutral wires. If the difference is more than a few milliamperes, it is assumed the the difference is leaking to ground, maybe through a person, and the GFCI trips.

Obviously, grounded and GFCI is best but GFCI alone is still good.

The only special requirements is that the GFCI outlet be marked “Not grounded” and any downstream outlet be marked “Not grounded, GFCI protected”.

BTW, for a downstream outlet to be protected, it must be powered from the LOAD terminals of the GFCI.

Radvylf Programs
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DoxyLover
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    Fully agree 6ma (milliamperes) is the imbalance that will trip a U.S. GFCI it is a little bite less than my electric fence feels like anyway. GFCI is safer than grounding alone. – Ed Beal Jun 13 '22 at 01:33
  • Good info thanks. So I would not need to replace every outlet in the room with a GFCI, just the one downstream and then the existing 2 prong in that room will also be covered? – richie894 Jun 13 '22 at 02:04
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    @richie894 Hopefully you meant the outlet UPSTREAM from the others, which is the correct method. The first outlet in the circuit would be the GFCI outlet and downstream outlets would be protected if connected to the load side if the GFCI outlet. Like others here said, code requires a label saying something like GFCI protected, no equipment ground. BTW, in a way, and others might snip me for this, but GFCI almost renders grounding obsolete for GFCI protected circuits. It's probably sacrilege for me to say that, but here goes! – George Anderson Jun 13 '22 at 05:07
  • I am sorry but something is not clear to me. If you have a three prong outlet, I would expect the GFCI device to be somewhere upstream of the outlet, otherwise what purpose is ground serving? Can you really have a three prong outlet without GFCI? – Vladimir Cravero Jun 13 '22 at 12:05
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    @VladimirCravero "GFCI" and the 3rd ground pin an an outlet are entirely unrelated. A GFCI detects an imbalance in the hot & neutral current and shuts off the supply, while the Ground pin provides a return path for fault current to flow should something like the enclosure of an appliance accidentally become 'hot' - leading to the 'regular' circuit breaker tripping due to the large fault current (orders of magnitude more than the GFCI trip current). You can have both, but they're not linked together. – brhans Jun 13 '22 at 12:48
  • Yep I understand how those works - it's just that where I live GFCI is just mandatory, and ground circuits are not sized for high fault currents - at all. I understand how that can help, but to be honest having a ground ckt without a GFCI seems more trouble than the little additional protection you get - and you need bigger ground cables. But that's at the very least debatable :) – Vladimir Cravero Jun 14 '22 at 09:36
  • @VladimirCravero I think it is American dogma from before GFCI was a big thing. Eventually we will probably get there! – le3th4x0rbot Jun 14 '22 at 10:14
  • @GeorgeAnderson: If a three-prong piece of equipment that's plugged into a GFCI "no equipment ground" double outlet develops an internal short from hot to the grounding pin, it will cause the ground pins of the outlet, and all exposed metal on anything plugged into them, to become live until an outside current path is provided from that to ground. I would think there should be a special classification of GFCI devices for use in no-equipment-ground scenarios which would weakly bias the ground pin to a switched neutral and trip if voltage appears there, but I don't know of any such thing. – supercat Jun 14 '22 at 17:24
  • @supercat I have to disagree. GFCI protection for circuits w/o a ground are commonly done. If, as you say, a ground fault develops in a connected appliance or device, yes, the frame or device metal parts will become energized. But the instant even a tiny bit of the current from the hot doesn't match the returning current on the neutral, the GFCI will trip. This is usually in the 5-7 ma range, threshold of feeling a shock is about 10ma. One more thing that ppl forget...GFCIs do NOT provide over current protection, only ground fault protection. – George Anderson Jun 14 '22 at 17:58
  • @GeorgeAnderson: A GFCI will limit the duration of a ground-fault event which exceeds 5mA. It will do nothing to limit the peak current. Attempting to connect a computer that is properly grounded to a USB device whose "ground" is connected to mains can cause severe damage to the computer and the device, even if a GFCI trips within 16ms. Further, if a devices that uses rectified mains voltage develops a short between rectified mains and the case, many GFCI devices may fail to detect the resulting DC current flow via an outside ground path. – supercat Jun 14 '22 at 18:33
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I also have a 1950s house with (until recently) most receptacles ungrounded. However, you may be pleasantly surprised, as I have been, to find good grounds available, despite currently having ungrounded receptacles. To summarize a little of everything, and add a few more things:

  • Ungrounded (2 prong) receptacles can often be replaced with grounded receptacles if there is a good ground (ground wire or, less frequently, metal conduit). This provides the default level of protection for most rooms except bathrooms, kitchens, laundry room, unfinished basement, garage
  • GFCI receptacles or GFCI breakers plus 3-prong receptacles can be used to provide equivalent protection to grounded receptacles if ground is not available. This is actually superior protection in certain respects, but does come at a cost as GFCI receptacles are more expensive than regular receptacles and GFCI breakers generally more expensive than GFCI receptacles. If you have an older panel then GFCI breakers may not even be an option.
  • Any 3-prong receptacles protected by GFCI that do not have an actual ground must be labeled "GFCI protected, no ground" (or similar language.
  • Tamper Resistant receptacles are required in most areas now and are definitely a good idea with little kids.
  • What you must not do is to bootleg ground to neutral. That will fool a 3-light tester but not provide any safety, and in fact be less safe that a 2-prong receptacle because it would give a false sense of security.
  • GFCI instead of ground provides life-safety protection but does not help with surge protection and other uses of the ground wire.
  • For bathrooms and kitchens (any location within 6 feet of a sink, tub or shower), always install GFCI, whether or not you have a ground wire available.
  • Properly installed, GFCI only needs to be on the first receptacle in a circuit and all later receptacles are protected. Doing this right is not rocket science, but requires a bit of thinking instead of mechanically replacing everything.
  • Old receptacle boxes may not be large enough for GFCI receptacles, and may not even be large enough for quality modern plain receptacles. Replacing boxes is easy in unfinished walls. In finished walls it gets more complicated, but not impossible, at least most of the time. There are rules for box fill, but the bottom line is that if you find it hard to fit new stuff in an old box, the old box is likely too small.
manassehkatz-Moving 2 Codidact
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    @richie894 Electrical box "extenders" are rings mounted to the front of an electrical box and provide additional depth/volume to the box. That may provide enough space to install a GFCI outlet without having to tear open the wall, but you'll have to decide if the aesthetics are OK for you. – Armand Jun 13 '22 at 07:34
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    Even relatively expensive GFCI breakers might seem cheap, compared to the cost of pulling new 3-wire romex through (and patching) walls. – spuck Jun 13 '22 at 22:49
  • @spuck Correct. But if OP's house is anything like mine (and we know it is at least a little like mine), the panel may be in no shape to accept GFCI breakers. – manassehkatz-Moving 2 Codidact Jun 13 '22 at 22:51
  • @manassehkatz-Moving2Codidact, Updating the panel may still be the "less work/money" option compared to pulling wire. Guess it depends on how many outlets/rooms the OP is talking about. – spuck Jun 13 '22 at 22:54
  • @spuck I'm still waiting on my panel (not emergency and electrician facing supply shortages too) and in the meantime dealing with my circuits one at a time. Haven't actually needed the GFCI-in-lieu-of-ground yet, but every house is different, but I have a few GFCI/receptacle on hand so if I get to a truly groundless circuit I can use it. – manassehkatz-Moving 2 Codidact Jun 13 '22 at 23:00
  • Someone told me that GFCI receptacles without ground would be too sensitive and might trip often without any apparent reason. Is there any truth to it? – Eric Duminil Jun 15 '22 at 09:50
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    @EricDuminil no – manassehkatz-Moving 2 Codidact Jun 15 '22 at 12:20
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You should take look at the Temper Resistant GFCI, for added on protection.

They have mechanical device inside (Shutters) preventing "objects" from been inserted.

shutter

However, when the 2 gang up they can destroy anything :P

Traveler
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    Technically required by code in most areas now. Annoying for adults. But a big deterrent for little kids, which is the goal. When I had little kids the temper resistant receptacles weren't really a common thing and it was all annoying plug in plastic placeholders except one different type of tamper resistant that I still have in one place in my kitchen. In any case, good idea if you've got little kids running around. – manassehkatz-Moving 2 Codidact Jun 13 '22 at 01:33
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    @manassehkatz-Moving2Codidact The TR receptacles have gotten better. The current TR GFCI outlets I've been putting in aren't annoying. – Armand Jun 13 '22 at 07:39
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Don't make it harder than it is

Except maybe a little harder.

I'm sure 10 times a day electricians have a conversation like "Well, you could just install GFCI receptacles" and the customer decides "Well I don't need an electrician for that".

And you can guess where this goes wrong. GFCIs aren't quite as simple as that.

Now, the key point to GFCI is that GFCI is not a receptacle. It is a zone of protection which protects any number of outlets or loads.

GFCIs come in many form-factors: GFCI+breaker, GFCI+switch, GFCI "just a GFCI" and of course the receptacle with which you are familiar.

Yes, obviously a GFCI receptacle protects its own sockets. But all GFCIs can protect, really, an entire circuit. Heck, in Europe, one GFCI protects the entire house - although that has some, um, compromises.

This is done via terminals that every GFCI has, called "LOAD". If a load or several loads or outlets has its hot and neutral wire attached to the "Load" terminals of the GFCI device, then they will be protected by that GFCI.

That is the only thing "Load" should be used for.

Of course the novice who is smarter than the electrician watches a Youtube video or two and is putting a GFCI at every receptacle, and using the "Load" terminals anywhere there are 4 wires. And then a ground fault trips them all, and they never figure out how to get them all reset!

So, the trick is to use one GFCI to protect the whole circuit.

Easy mode is to use GFCI breakers if your service panel has modern breakers available. These are more costly than receptacles, though.

The second option is to carefully map every circuit (via trial and error disconnections). Locate the first receptacle past the service panel, and put the GFCI there.

Either case requires identifying all the receptacles on that circuit and marking the receptacles (as relevant):

 GFCI Protected
 No Equipment Ground
 Reset west wall this room

(the last line is purely optional). Making your own labels is legal so long as they are not handwritten.

And you are free to convert them to 3-prong outlets, even though they don't have a ground. Plain 3-prong outlets will suffice, but they probably need to be Tamper Resistant.

Or, grounds can be retrofit

But grounding protection is not as good as GFCI protection for humans.

Retrofitting grounds is allowed under certain fairly generous rules, and is handy when you have electronic equipment that needs grounding to suppress static electricity to reduce ESD damage.

Don't forget AFCI

AFCI is Arc Fault protection. It is designed to detect failing wire connections that are likely to start a fire. It "listens" electronically for the "sound" (waveform) of wire arcing. That can be just the thing for a house with old and suspect wiring, particularly if the wiring is aluminum.

(Other measures can help greatly with aluminum wire; I feel those + AFCI breakers make aluminum perfectly reliable).

AFCIs also can help with a child sticking 2 things in the hot and neutral slots, which a GFCI cannot detect if someone is being shocked between hot and neutral (the GFCI thinks that's just a normal load, but the AFCI notices the current curve isn't normal).

Harper - Reinstate Monica
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You specifically asked about "safest" given the context of 4 and 7 year old kids. The answer is ungrounded GFCI Receptacles.

  • You would add a very valuable electrocution prevention feature that a well ground product still does not offer: The presence of a leakage current that might be leaking through a human. (Leakage Current means more than 6 milliamps of current flow is happening elsewhere, not being looped back through second prong of the plug.)
  • You can save money on multiple GFCI Receptacles by updating "the first" ie. mapping out where the daisy-chain of several outlets begins. Upgrading the outlet first reached by the wire from the fuse box and connecting the downstream outlets on the optional LOAD side. Swap those with 3 prong outlets, and label them "No Equipment Ground" and "GFCI Protected" (You can find mapping advice elsewhere. Please confirm all imagined downstream outlets with a GFCI outlet tester.
  • NOTE: Please also know that your house was wired to power powering desk lamps, not space heaters or air conditioners. They may work, but only voltage-drop measurements under load tests will detect degraded connections in the walls or service panel. Too much voltage drop means some connection is getting quite hot, which left unrepaired can burn your house down!

Ref: NEC 406.4(D)(2) Non–Grounding-Type Receptacles NEC Snippet

JamieRI
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The US National Electrical Code allows GFCIs to be fitted with missing grounds in retrofits, but NOT in new installations.

What that says to me is that the people writing the code thought that GFCIs with missing grounds were a "lesser evil" than the realistic alternative of people using cheater plugs or cutting off ground pins but that they did not consider GFCIs a proper replacement for grounding overall.

Proper grounding and breakers should disconnect the fault as soon as it occurs, a GFCI with a missing ground cannot do anything until after the shock starts.

Also, grounds aside if the house was wired in 1955 and hasn't been rewired since I would be very worried about the condition of the wiring. Afaict 1955 was before PVC became common and old rubber often degrades over those kinds of timescales.

Peter Green
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    The GFCI vs. grounding is a bit more complicated than that. From a pure life-safety standpoint, GFCI can actually be better than grounding alone. But there are other aspects (e.g., surges, noise, etc.) that GFCI does not resolve. When functioning properly, GFCI actually reacts much faster than a regular breaker to anything except a "dead short". – manassehkatz-Moving 2 Codidact Jun 13 '22 at 02:48
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    You seem to be confused. “Proper grounding and breakers” are not a substitute for GFCI in any way. Not every fault is a dead short to ground. If a person manages to touch hot and ground, a 15A breaker (best case) is not going to save their life! A 6ma GFCI will. – nobody Jun 13 '22 at 02:51
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    Case in point, I had a fault in my hot tub heater. Corrosion developed on the power terminals and electrified the shell of he heater, electrifying the water. The leakage was nowhere near enough to trip the 50A breaker supplying the hot tub, but it tripped the GFCI immediately. – nobody Jun 13 '22 at 02:54
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    I've heard a quick and dirty summary that breakers are to protect equipment, and GFCI is to protect people. – Michael Richardson Jun 13 '22 at 21:39
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    @MichaelRichardson: Breakers are primarily to prevent fires, which could endanger both equipment and people. A GFCI without an equipment ground will protect people, but may fail to protect equipment from some ground fault scenarios. – supercat Jun 14 '22 at 21:57
  • You wrote "Proper grounding and breakers should disconnect the fault as soon as it occurs..." Which is only true for an appliance with a low resistance, non-arcing, short of the line/hot lead to metal chassis, plugged through properly assembled attachment plug, into tight recepticle, a branch circuit with still tight connections on every screw and wire nut in the hot AND carefully wired ground wiring that is passing this fault current, to proper fuse / still working breaker that hopes the fault current is >= 150% of fuse rating!! So delicate with untestable performance. A false promise!! – JamieRI Oct 19 '22 at 13:39