What is a Bootleg Ground?
The electrical system is one of the most complex, and difficult to understand system in your home. One problem we find quite frequently during our inspections is “bootleg grounds.”
A bootleg ground, also known as a false ground, is when the grounded and grounding screws of a receptacle are bonded with a jumper, giving false readings of correct wiring.
In simpler terms the neutral wire (white wires) is connected to the ground screw (green screw) of a three-prong outlet with a jumper wire in order to give a “correct wiring” reading on a 3-light tester.
In Richmond, we. have a lot of older homes. I have personally inspected homes from the 1800’s, but early and mid 1900 homes make up the bulk of my inspections. A lot of these homes are bought by investors, upgraded, and sold again in a short period of time.
Many people call these flips.
When flippers attempt to upgrade the electrical system on an older house, the outcome is typically below par. They often upgrade the outlets from two prong, to three-prong receptacles in order to appeal to home buyers. New receptacles are great, right?
However, without upgrading the wiring from a two wire system to a three wire system, there won’t a be third wire (the ground wire) to connect to the ground terminal.
Most of the time they simply leave out the grounding wire, which is defect all in its own.
However, sometimes they get sneaky and “bootleg” the ground.
This is when they use a jumper wire to connect the neutral screw, to the ground screw. This gives a false reading on some testers that the outlet is wired correctly, and generally tricks most home inspectors.
Why are Bootleg Grounds Unsafe?
I will first explain the function of the the neutral and grounding wire.
The proper term for the neutral is the “grounded conductor.” It’s function is to return current, that has passed through a fixture such as a light bulb, (load) back to the source. During normal operation, there is current flowing through the neutral.
During normal operation with a properly functioning system, the “ground wires” do not carry any current. The proper term for what most people commonly describe as a “ground wire” is an equipment grounding conductor (EGC). EGCs bond non-current-carrying equipment such as metal appliance casings (toaster), metal conduit, junction boxes, and outlet/switch boxes, to the service panel, and the neutrals and EGC‘s within the panel. In the event that a “hot wire” comes into contact with equipment, the EGC will allow enough current to flow back to the panel and trip the breaker (or blow the fuse). If the EGC was not there and a person came in contact with the equipment, and was also in contact with the ground, s/he could complete the circuit and receive the flow.
So let’s say you have a toaster oven or Fridge (or anything with a metal chasis or frame) plugged into an outlet with a bootleg ground. The neutral is connected to the ground though, which as mentioned, is bonded to the metal case of the toaster or fridge. An unsuspecting user has a risk of electrocution when using the toaster or fridge.
How Do you Test For Bootleg Grounds
Unfortunately, a most home inspectors are not going to catch this during their home inspection. Most home inspectors carry a simple three light electrical tester. They plug the tester into an electrical receptacle, and the three lights will light up in a specific pattern to signify if the wiring is correct, or defective.
However, these testers have limits. They are only about $10 after all.
The biggest limit is that they can only detect one defect. They would not be able to detect reverse polarity and open ground for example.
They also do not test for bootleg grounds.
A more robust circuit analyzer such as a suretest circuit analyzer is needed to test for bootleg grounds and the even more dangerous reverse polarity bootleg ground wiring.
This is the Best Circuit Analyzer For Detecting Bootleg Grounds
Are Bootleg Grounds Legal?
I once had a licensed electrician tell me that bootleg grounds were because the grounded conductor and the grounding conductor were bonded in the main panel, so it must be fine if they’re bonded after the main panel.
Of course, he was wrong. The NEC is clear:
250.142 (B) Load-Side Equipment. Except as permitted in 250.30(A)(1) and 250.32(B) Exception, a grounded circuit conductor shall not be used for grounding non–current-carrying metal parts of equipment on the load side of the service disconnecting means or on the load side of a separately derived system disconnecting means or the overcurrent devices for a separately derived system not having a main disconnecting means.
The installation of a jumper wire will bond the grounded and grounding conductors and ” create a parallel path for neutral current which allows neutral current to flow on the neutral conductor as well as the fault current path.”
An Illustrated Guide To Wiring a Safe Home
How Do you Repair Bootleg Grounds?
Repairing bootleg grounds is a simple, albeit a tedious, job.
Removing all the jumper wires from all the receptacles will leave the home with ungrounded three prong receptacles.
The National Electrical Code (NEC) gives us three options for dealing with this situation.
“406.4(D)(2) Non–Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (D)(2)(b), or (D)(2)(c).
(a) A non–grounding-type receptacle(s) shall be permitted to be replaced with another non–grounding-type receptacle(s).
(b) A non–grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles or their cover plates shall be marked “No Equipment Ground.” An equipment grounding conductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
(c) A non–grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Where grounding-type receptacles are supplied through the ground-fault circuit interrupter, grounding-type receptacles or their cover plates shall be marked “GFCI Protected” and “No Equipment Ground,” visible after installation. An equipment grounding conductor shall not be connected between the grounding-type receptacles.
Informational Note No. 1: Some equipment or appliance manufacturers require that the branch circuit to the equipment or appliance includes an equipment grounding conductor.
Informational Note No. 2: See 250.114 for a list of a cord-and-plug- connected equipment or appliances that require an equipment grounding conductor.”
In other words, the best option for dealing with this would be removing all the jumpers, and adding GFCI protection to the circuits.
Of course, this should be done by a qualified electrical contractor.
As an amazon associate I earn from qualifying purchases