What is a Bootleg Ground?
A bootleg ground, also called a false ground, is a situation that is created when a jumper wire is installed on an electrical receptacle between the ground screw and the neutral screw.
Installing this jumper is normally done when a two-prong receptacle is replaced with a three-prong receptacle. The jumper is added in an attempt to ground the receptacle.
There are two main thought processes that cause people to add the jumper wire.
1. It is done out of ignorance (not understanding that this does not properly ground the receptacle.)
2. It is done out of a blatant attempt to fool an electrical tester used by someone such as an electrician or home inspector.
I believe that most of the time it is done out of ignorance, because most people would not do this if they understood the dangers of a bootleg or false ground.
Why do People Create Bootleg Grounds?
Prior to about 1965 homes were wired with a wiring system that only included two wires- a hot and a neutral wire and not a ground wire. When the receptacles were installed, they only had two prongs.
Often when people update their home, they like to install new electrical receptacles. Although you can purchase two-pronged receptacles, many people like to install three-prong receptacles so they can plug in grounded plugs without having to use an adapter.
Unfortunately, most people who update the appearance of their homes do not actually rewire the home. Without running a new set of wires that includes a ground wire from the breaker panel to each newly-installed receptacle, the new receptacles cannot be grounded.
Rewiring a home or running wires to some receptacles is not easy and is quite expensive.
As a result of the difficulty and expense of running new wires, the individual installing the new three-prong receptacle will sometimes install a jumper wire between the ground screw and the neutral screw.
In a sense, this “grounds” the outlet, and makes it appear grounded when a receptacle tester is plugged in.
People often justify this bootleg ground by saying that since the ground and neutral wires are tied together at the electrical panel, it’s ok to tie them together at the receptacle.
While it is true that they are connected at the electrical panel, they cannot be tied together at the receptacle.
Bootleg grounds are specifically PROHIBITED by the National Electrical Code because they create a dangerous situation.
Why is a Bootleg Ground Dangerous?
Before explaining why bootlegs are dangerous, I will start with a quick and simplified explanation of how an electrical circuit works.
Electricity flows from the breaker panel to the receptacle through the hot (black) wire. From the receptacle, it then flows through the cord to the device that is plugged in and then back through the cord to the receptacle. Finally, it flows back to the breaker panel through the neutral (white) wire.
Summed up, only the hot and neutral wires are designed to carry current. On a properly grounded receptacle, the bare ground wire is not designed to carry current under normal circumstances.
The ground wire should only carry current in a fault situation, and it carries this current in order to trip the breaker and de-energize the circuit to protect people in the home from possible electrocution.
Bootleg grounds are dangerous for several reasons.
Disconnected Neutral with Bootleg Ground
First, let’s suppose that you have a receptacle with a bootleg ground. If there is a problem on the receptacle containing the bootleg ground where the neutral wire becomes damaged or disconnected somewhere, then anything that is plugged into that receptacle will become energized and will put anyone in your home at risk of being electrocuted by simply touching the device that is plugged in.
With a disconnected neutral and a bootleg ground, the frame of anything plugged in will be energized with 120 volts.
For example, if a refrigerator is plugged into a receptacle with a bootleg ground, then the entire body of the refrigerator will be energized to 120 volts. Anyone who touches that refrigerator will be in danger of being electrocuted.
Reverse Polarity with Bootleg Ground
Second, if you have a bootleg ground in combination with a reverse polarity (hot/neutral reverse), then you have the same situation described above – the body of anything plugged into this receptacle will be electrically energized and an electrocution hazard.
Bootleg Ground on a GFCI Protected Receptacle
Third, GFCI-protected outlets downstream from a receptacle with a bootleg-ground may not trip in the event of a ground-fault situation. Since GFCI’s are designed to protect the home’s occupants from possible electrocution, a non-tripping GFCI receptacle puts you more at risk of electrocution. Read more about GFCI receptacles here.
Put another way, proper grounding is designed to make a home’s electrical system safer and to protect its occupants. A bootleg ground does just the opposite – it makes the home’s electrical system more dangerous, and it puts the occupants more at risk.
How to Know if Your Home Has Bootleg Grounds
If you live in a newer home, then you don’t have too much to worry about as far as bootleg grounds.
Most homes built since the mid to late 1960 should have been wired with a three-wire system and should have ground wires to each receptacle.
If your home meets three conditions, then there is a chance that it has bootleg grounds. Those three conditions are the following:
1. It was built prior to the mid-1960s,
2. It has grounded receptacles,
3. And it has not been rewired.
A simple electrical receptacle tester like that shown below will NOT tell you if you have any bootleg grounds.
If you suspect that one or more receptacles has a bootleg ground, then you could remove the cover and see if there is a jumper wire. NOTE: You may have to loosen the receptacle and pull it out of the wall to see the jumper. TURN THE BREAKER OFF BEFORE PULLING THE RECEPTACLE OUT OF THE WALL.
You can also have an inspection by a licensed electrician or a home inspector who uses a more specialized device, such as a Sure Test Circuit Analyzer, to test the receptacles.
Look at the two photos below that compare the indications you get on a simple three-light tester versus a SureTest circuit analyzer when these two devices are plugged into a receptacle with a bootleg ground.
Standard receptacle tester shows this receptacle is properly grounded
The “F” on this tester shows the same receptacle has a false or bootleg ground
What Should You Do if Your Home Has Bootleg Grounds?
The short answer is that you should have them corrected by a licensed electrician.
If your home uses an older wiring system that does not include a ground wire, then the receptacles in your home will not be grounded without rewiring your home. Having said this, you do not have to rewire your home to gain some protection.
There are several things that you can do. You can leave two-pronged receptacles installed on all of the circuits without a ground wire. This will prevent giving the false sense of security that ungrounded, three-prong receptacles can give. (You can read more about the differences between grounded and ungrounded receptacles here.)
Another thing that you can do is to have GFCI-protected receptacles or breakers installed on all of the ungrounded circuits in your home. This will greatly increase the safety of the electrical system in your home. (See my video showing how to do this.)
© 2019 Mike Morgan
This article was written by Mike Morgan, the owner of Morgan Inspection Services. Morgan Inspection Services has been providing home, septic and well inspection services throughout the central Texas area since 2002. He can be reached at 325-998-4663 or at mike@morganinspectionservices.com. No article, or portion thereof, may be reproduced or copied without prior written consent of Mike Morgan.
