A common problem found in old houses is the presence of ungrounded outlets. Either you’re stuck with old fashioned 2-prong outlets that won’t fit your 3-prong devices, or someone replaced the old outlets with 3-pronged outlets that don’t have a ground wire.
The 3-pronged outlets are often a sheep in wolf’s clothing since they look like modern outlets, but don’t have any of the protections.
Important Disclaimer: While I am a licensed contractor, I AM NOT a licensed electrician. So, before you put any of this information to use, check with a local electrician first. Electrical work is nothing to take lightly as you can cause fires or electrocution. Don’t do any of this work if you’re not qualified.
Since the early 1960s, most electrical codes have required a ground wire to be run to all outlets and appliances, but prior to that time, most wiring was just 2 wires (hot and neutral).
The ground wire provides an alternate path for electricity that may stray from an appliance or product to make its way safely back to the breaker or fuse box and exit the building into the main ground connection.
Electricity is like water in that it always chooses the path of least resistance. Without a grounded outlet, that path is either through your appliance which will fry your TV, computer, microwave, etc. or in the worst case, through you! You may think that having a surge protector is enough, but surge protectors only work properly when attached to a grounded outlet.
There are two possible ways to fix the issue of ungrounded outlets and I’ll walk you through both of them.
How To Fix an Ungrounded Outlet
The ideal way to repair an ungrounded 3-prong outlet is to establish a continuous electrical path back to the main panel. If the outlet is installed in a metal box and that metal box has metal conduit wiring (BX cable) all the way back to the panel, then you can ground your outlet with just a little work.
To make sure you have the right setup, you can use an inexpensive pig-tail electrical tester. With the circuit energized, touch one end of the tester to the hot wire (the smaller slot on the outlet) and one end of the tester to the electrical box. If the tester lights up, the box is grounded. If you get no light, then there is no ground and this method won’t work for you. Skip down to Option #2 below.
If the tester lit up, then all you need to do is run a bare copper wire from the ground screw on the outlet and attach it to the metal box. This will provide a ground using the equipment already in your house.
If your outlets are installed in a concrete wall, there is a possibility of getting a false reading, but for wood frame structures, this is a good test. If you are dealing with concrete walls, call an electrician to check things out or try Option #2.
Option #2 Install a GFCI
So, your house doesn’t have metal cable and you can’t get a grounded outlet that way. All is not lost. There is another option that is not quite as good as an equipment ground but will keep you safe just the same.
You can swap out your standard outlet for a GFCI outlet on any ungrounded outlets to provide protection from shocks and surges; however, you will need to add a sticker to the GFCI outlet that reads “No Equipment Ground” which comes with every GFCI outlet. This lets other folks understand what is happening behind the walls in the future.
A GFCI will “sense” the difference in the amount of electricity flowing into the circuit to that flowing out, even in amounts of current as small as 4 or 5 milliamps. The GFCI reacts quickly (less than one-tenth of a second) to trip or shut off the circuit.
So, there you have it. If you have ungrounded outlets, you’re not stuck having to pay thousands of dollars for a complete rewire of your house. There are options to keep your family and electronics safe.
Founder & Editor-in-Chief
I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.
jump the ground to the neutral on back of receptaclel and install . be certain the neutral is the wire going to the grounding buss bar in panel
THis typical of a home owner the ground is a current carrying conductor. This not the way to do it . follow the instructions in this post.
This will only give you a false ground. The idea is if the neutral wire fails the ground will act as a backup. Tying the two together at the outlet is unsafe and illegal!
The neutral wire actually returns unused 120V to the alternating current system. Your post is not only dangerous, but highly illegal according to the NEC (National Electric Code). But…..on the other hand, ignorant homeowners like yourself are keeping me very busy….
NEVER connect the neutral and the ground wires or terminals at an outlet.
@Evan Brumbaugh
The ground wire does not have anything to do with the neutral wire failing or shorting out.
@Dan Brasier
I assume you don’t actually believe the neutral returns “unused” current. The neutral is just as essential as the “hot” on a typical 120V circuit, and all of the electricity flowing through it is “used.” The neutral just happens to also be grounded. Spot on about the dangerous and illegal part, though.
Are you an idiot?? Not to be rude. But if you are not being helpful. Please stay out of conversation. Peoples lives are at stake. Not just money.
You have options:
-install 2 prong plugs
-install a GFCI at every location
-install a GFCI at the FIRST location feeding the rest of the receptacles on that particular circuit. Do NOT ground any of the other receptacles.
-jump a ground wire to every receptacle location of your house to the nearest equipment ground.
-re-wire your house
-get lucky and have grounded metal boxes that you can pigtail to
The thing that makes me the most furious when I go to a home after an inspection is that inspectors have no idea how a GFCI tester works. Every time they test a GFCI in an ungrounded system they report that the GFCI needs to be replaced. It isn’t true. A GFCI tester does NOT work on an ungrounded system. It checks levels between Hot and ground. Not hot and neutral. I digress….
There is nothing wrong whatsoever with changing over to GFCI receptacles. It’s obviously not the best option, but let’s face it…you probably can’t afford…not do you want to gut your original 1880’s home to rewrite it. I’m an electrician and even I can understand that.
A GFCI will rotect you from a fault unless the GFCI fails. In my lifetime, I’ve only had GFCI’s fail to PROVIDE power…not fail to trip.
There’s my two cents. Hope this helps.
Selling older house with outlets that do not have a ground wire. Buyer has reguestered that all outlets be grounded. Will the GFCI method work?
No, not true, umreliable because recepticles down line from first GFCI,may find their own ground rendering any further recepticles downline from that one are not protected!
Not true about GFCI installation to cure the ungrounded receptacle issue. It is still ungrounded and may or may not activate. Hire an electrician to install grounded receptacles that are grounded to the system.
are you saying get the house rewired with wire with a ground. This is very expensive. The house was built per code in 1950. When I use a tester it shows OK. Does not show open to ground. How can that be?
Some older houses have a bare copper ground wire in the wall that is used to ground the metal boxes. That ground transfers to an outlet thru the metal mounting straps.
According to the NEC, this is an acceptable method to protect people in contact with ungrounded outlets. Sometimes rewiring a home is not a feasible option for people. That’s coming from a licensed electrician.
The purpose of installing a GFCI is to protect against electric shock. Installing a GFCI does not magically make the outlet(s) grounded. If you have a metal toaster, and plug it into an ungrounded receptacle, the frame of the toaster could become live if something is wrong with the toaster. It will stay live until the frame contacts something else which can take that live current back to the panel, completing the circuit. That something else could be YOU. Such an inadvertent circuit may cause an overload, but a circuit breaker or fuse will not trip fast enough to save your life. A GFCI will trip fast enough to save your life–that is its sole purpose in life. A GFCI does not use or require the ground wire to do its job (contrary to a misguided over-dramatized episode of CSI). Ultimately, the best solution is to have a qualified electrician re-wire the building. It’s expensive and time consuming, but it only needs done once.
Dennis said voltage goes down current goes up.
Voltage is the pressure that pushes current.
When voltage does down (a voltage drop due to an increase in resistance) then current goes down.
Joe Glassford http://www.vestest.com
Is it necessary to replace each outlet with a GFI, or just the first one on the circuit or maybe the first one in the circuit in each room?
The first one on the circuit would suffice
Regards. I live in an old house, built in the early ’60s and not in USA, which has only outlets with two prongs. I have always thought that the whole installation is not grounded. And when connecting UPSs to any of the outlets, a faulty installation warning LED in the rear of the units turns on.
A neighbor has told me that he had that situation fixed by replacing outlets in question with three-pronged ones which have wires that connect to a metal stick literally grounded in the soil of his garden.
Is that a real, device protecting and, overall, safe solution – to humans, pets and plants around? If so, what are the technical terms I should look for to get informed. Thanks in advance for your attention.
The faulty wiring showing is probably just the polarity of the wires reversed. A ground stake in your garden would give you ground, but it could result in your neutral becoming grounded at that point which could be hazardous in the event of a fault. Replacing the first receptacle in the circuit with a GFI works… As long as you can find out which is first.
As an electrician I would install a junction box next to your panel and wire faceless GFCI units in to be sure the whole circuit is protected. This would be safer than either method explained in the post.
Can a GFCI breaker be installed to take the place of adding a junction box to your panel and a GFCI receptacal and do the same thing?
Yes, you can install a GFCI braker in each one of the circuits you need to protect, avoiding the need of installing GFCI plugs, doing junctions or adding pigtails to each plug to a metal box. That’s with the purpose of protecting kids, pets and some appliances. But the best thing to do and highly recommended is to ground the outlets to the panel
What about grounding to a metal Air conditioning duct?
A ground is literally a rod driven into the soil, so yes, your neighbor is correct. In US homes, there’s a grounding rod with a copper conductor tied into the breaker box. All modern wiring has a hot, neutral and ground. The ground is tied directly to the grounding rod through the breaker box.
While it is true that you can run a new ground around to your receptacle by driving a ground rod and attaching to it you must also bond this ground to the ground in your panel. Transformers work by sensing voltage to ground, ground reference, and establishing a separate ground which is not bonded to the system can result in wild voltage fluctuations and even hot neutral and/or ground. Code only permits bonding the ground and neutral at the service entrance. If you can locate the system ground at a point beyond the service entrance you can bond your new neutral to this point, i.e.; most homes with ungrounded receptacles do have grounded receptacles at the kitchen and bath.
Connecting to a “garden ground” as you describe is not an acceptable solution. The ground system connects to the Earth to eliminate the voltage potential between the neutral and the earth. However, for the ground system to protect you from a short circuit, there still needs to be a quality connection from the ground system to the neutral. This is always accomplished at (and only at) the main disconnect or service panel.
Ground (earth) rods are safe for humans and pets and plants except when a surge (such as lightning) is being diverted.
I keep reading that adding GFCI to ungrounded receptacles is “safer” or “better” but not as good as being grounded. Scott’s comment was that it is “not great”. Can someone still get shocked or electrocuted?
There is always a risk though death on 110v is not likely.
Scott, this is a popular misconception. Statistics show that around 90 percent of electrocution deaths are a result of contact with residential voltages, with the vast majority of those being with 110 volts. It is the amount of current passing through thenhuman body that is of greater concern than thenvoltage level. It takes a mere 50 milliamps, that’s 0.05 amps, to cause cardiac arrest. Most residential circuits are capable of delivering a minimum of 15 or 20 amps of current. That’s 300 to 400 times the amount of current required to kill a human. It seems counter intuitive that most electrocutions are the result of such comparatively low voltages, but the reason is that most people working on higher voltages are trained in proper electrical safety procedures, whereas the average homeowner or handyman attempting residential electrical repairs and alterations is not. Play it safe and be absolutely sure all circuits are deenergized before handling.
Correct. Also important to know is the path that electrical current passes through your body. Cardiac arrest happens when current passes through your heart exiting to the part of the body that is grounded eg left hand contact to right foot path = heart shock
As mentioned there, it is the amperage that counts. Most time these fatalities happens when there is a good ground touching the person like something wet (bath tub, shower and so on, like washed floor plus the factor that person doesn’t have anything insulating him or her for ground. As it happens I have personally gotten zapped by 220V in Europe when I was about 7years old by bad connector to Christmas tree and then number of other occasions same voltage and then some 15+kV from the flyback transformer in TVs. So the biggest danger is being bare footed when playing with electricity. I’m not professional electrician, but I have wired number of my own places and some of others, all that have been inspected and passed without problems and in one occasion told by inspector to fix work that professional had done and the “customer” didn’t tell me about. The guy had left a mess behind. I have studied hydro power in the college and worked in the companies that dealt with electrical installation and I had known the codes of those places where I did the work and as said I never intended to work to anybody else but for my own place, but ended up in couple of emergencies just hoping the inspector doesn’t ask my license. I’ve seen so bad installations that I wonder how those got through inspection in the first place. Some that I wouldn’t myself touch mile long tool. Like hows the place when you change the ceiling fan and all the insulation falls down. So grounding is the only way I see to go safely as people do all kind of things if there seems to be ground and isn’t. Like kitchen and microwave and portable dishwasher. Talk about wet. No ground in whole kitchen. So that not to have to rewire the whole house? Get grounded receptacles in strategic places. There are equipment that really like to have real ground so those special receptacles wouldn’t be the best choice. Now that just me and I have my own requirements that many other’s don’t, but there are old housed there that rewiring would be only safe way to go. Like that house that insulation came down. As I’m from Finland I don’t remember what it is called, but the tar over the wire through ceramic though insulators and both hot and cold going some distance from each other. By now they are ready to burn the house. Get the roof leaking to attic and there we go. Call that fire department. All the old papers and so on giving good fuel.
If a GFCI outlet is installed in place of a 2 prong plug will it protect plugs wired off of that outlet or does a GFCI outlet need to be installed in place of every 2 prong outlet.
Yes it will protect the plugs branching off of that circuit
When connecting GFCI receptacles you need to make certain the other circuit receptacles you want to protect are connected to the LOAD terminals or they will not be protected. When you are finished with your installation, press the test button on the GFCI and make sure the other receptacles are de-energized.
Bought a 1953 house where tester showed open ground on one outlet. Replaced with GFCI outlet and still shows open ground. Not sure this is safe.
That’s because your GFCI isn’t grounded—they don’t magically provide grounding, just over/under current protection.
GFCIs do not magically provide grounding, but they do not provide “over/under current protection.” That terminology implies they protect against brownouts, which they do not. Since all electricity must flow in a loop called a circuit, the GFCI monitors how much electricity is going into the circuit past it, and how much is coming back through it. The amount coming and going should always be the same. If it’s not (especially if more is going in than coming back) then electricity is “leaking” out of the circuit through another path. The GFCI will very quickly disconnect itself (and everything else connected beyond it), just in case that leaking electricity could be going through a person.
My 1962 house has a thin bare wire connected to the metal outlet box.If I run a grounding wire from the new three hole receptacle to the box, is this adequate?
That would be a question for an electrician.
Pretty sure my comment was aimed at a GFCI comment before.
Back to the original comment:
The small thin wire is considered a bonding of the raceway to the system. This is perfectly acceptable and still a common method with AC cable; no MC. Since there is a metal box, the receptacle is considered grounded to the box as long a the paper is removed that holds the screw in place at each end and must be drawn up tight to metal. If the box is set back, the ground will not be considered effective. The receptacle is considered un-grounded once it is removed from the box. Using a grounding wire connected to a grounding screw in the box or some means would also consider the device grounded. The device box must be equipped with a #10-24 machine thread hole. A GFCI Receptacle could be used for the same reason, but you must remove the paper from the screw.
Thank you for the response.
For the receptacles that I’ve replaced, I’ve used a pre-made grounding wire from the hardware store.(They come in a package of 3 or 4,the wire being about 7 inches long of a good gauge. Connecting the spade end to the receptacle and the other end,with a terminal with a hole,with the supplied screw,going into one of the holes of the metal box.
I haven’t found any new simple 2 prong outlets lately.
Yes
Yes
It is adequate as long as the bare wire is continuous and unbroken and connected to a grounding source. Either at your panel or a cold water pipe or ground rod.
A stopgap I have used on ungrounded outlets is to run a green insulated 12 ga wire with the existing romex to a grounded device. I know this implies some lack of protection for the grounding wire, but feel it is still a satisfactory interim improvement short of rewiring (no pun).
On the first issue, the BX cable, unfortunately that wont really work. First the outer metal sheathing is oily and the individual metal pieces are not good conductors so it would be questionable if you could carry the amps required in an emergency back to the breaker to clip it – the problem is at any given time the ohms (the resistance) in that outer sheathing might change. They do make BX with a ground, but it would already have the green hanging out of the conduit in that case and they probably would have used it already if they spent the extra for it. Plus the oil on the BX would not pass in the gfci computer (the internal samples would trip the gfci, it’s a very finiky device inside, any miswiring will just trip the gfci).
Running the dedicated ground wire either out through the outside wall to a ground, or to a common ground is the only way to get a connection good enough to carry a short back to trip the breaker and alow the GFCI “test” on the new gfci to actually pass.
If you were to swap a standard outlet with a gfci, the new gfci would not turn on until the ground is set up right. It wouldn’t turn on if you jumped the white over to the green either. The GFCI requires a dedicated white (neutral) and green (ground) in order for the computer to pass its test.
Hi Scott…my son bought a early 1900’s home…it still had an outhouse out back…they upgraded some of the wiring…but not all of the house…there are 2 prong outlets all through the house…I am going to check them out to see what we can do to make them safer…he also is having trouble with outlets in the kitchen…I hope I can add some new outlets and maybe run him a dedicated wire for his fridge…I sure appreciate your article…I am sure to enjoy your blog…Thanks so much…
I’m beyond happy I found your blog! I am buying a 1925 bungalow in North GA and I no longer feel alone, haha! From the lack of insulation, the plaster walls, chipping paint, crawlspace critters, to the ungrounded outlets, it’s all addressed here and I’m comforted to read that everything can be fixed. Thanks!
Welcome to the tribe Kristen!
Thank you for the info! Going to look into the
GFCI route for a few stray plugs I have!
Great to know, Scott! Thanks for sharing your knowledge. We have a little bungalow in College Park that we adore and may need to call on you in the future.
Great to meet you @flblogcon today. Let’s stay connected.
Great meeting you too Diane! We definitely need to stay in touch. Love your site!
I’d say GFCI would be the safer way to go here. Either way it’s necessary to place backup batteries on expensive electronic equipment (i.e. TV’s, audio equipment, computers). For surges, yes, but more so for brownouts. When the power fluctuates negatively it can have ill impact on electronics.
I am a little concerned about the recommendation to use the armored cable as a ground path without the home owner making sure that they know what type of cable that they have. For example, the last two houses that I have owned have had un-bonded BX cable from the 20’s and early 30’s. Bonded BX cable would have a bonding wire running in the cable to make sure to tie the coil of metal in the cable together in a low-resistance manner, and until the 60’s, most BX does not have this bonding strip. So, even if the meter shows 110V from the hot to the metal box, where it is being grounded through the BX metal jacket, that could be a very high resistance path. Once current is actually flowing through the non-bonded cable in a ground fault situation, the high resistance could cause the cable to become a heating element and become a fire hazard. Additionally, the NEC does not list even bonded-BX as a code-compliant grounding method (even though people do use this method whether they should or not). If you do an Internet search you will see many arguments for and against using bonded armored cable as a ground. Even if a homeowner knew 100% that they had bonded cable, and that it was a low resistance ground back to the box, there are enough questions that I would not feel comfortable advocating this method on my website.
Nick, thanks for your comments. I appreciate your insight on this. To be clear I’m not advocating, just trying to educate. There are always different solutions that work best in a particular circumstance. Ultimately, it’s up to the professional electrician to decide, but homeowners should know about their options so they can discuss them with the pros instead of blindly following what us contractors suggest.
Ground should be sized for current load of receptical eg 15 amp = 14 ga copper ground wire
Good writeup. One caveat on the GFCI approach: While it protects humans, it doesn’t protect computers and other sensitive electronics as well as a proper grounded outlet would.
Chris, I have heard that argument from a lot of very smart electricians while at the same time heard the opposing view from other electricians just as smart if not smarter. I’m not sure I buy that it won’t protect appliances just as well. From the explanations I’ve heard it make sense that it would protect both equally as well. But then again I’m not a licensed electrician. I’ll have to leave it up to the pros to decide. I think ultimately it depends on one electricians preference over the other.
A typical GFCI outlet is protection for personnel. It is designed to trip at 5ma. It has nothing to do for appliances. If you plug an appliance into a GFCI outlet or a GFCI protected Circuit and it trips, most likely the appliance is faulty and should not be used. Surge protectors help protect your equipment from surges by clamping the voltage to a specific value. Most surges are internally based and not externally based. An example is when the AC starts and your lights dim. The inrush of current causes voltage to drop, then at run, there is a sudden increase in voltage. That is surge. Should this start up last for some long duration such as lock rotor, this condition could cause a brown out or undervoltage condition. If it holds long enough, it will cause other breakers to trip from an over current state mostly on motors. Voltage goes down, current goes up. Anyhow all this being said, If you have an ungrounded system Properly installed, do not add a grounding conductor or connection anywhere in the system unless you are doing all of it from the panel to the last device. That would include ground rod, Neutral Bonding, and water pipe ground. Most shocks in a 2 wire system were between the line and neutral. Not so much line to ground as the ground did not exist. If someone got shocked line to ground, there would be a neutral conductor actually bonding to a grounded surface to create the condition somewhere in the system.
To some it up, using GFCI on all ungrounded outlets are ok?
Not great but better than nothing.