What is a Bootleg Ground?

Milner_Jeff 083

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.” 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.

When investors attempt to upgrade the electrical system, the outcome is typically below par. They often upgrade the outlets from two prong, to three prong types. 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 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 is this a problem?

I will first explain the function of the the neutral and grounding wire.

duplex-receptacle

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 lets 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. When you wake up and attempt to toast your bagel…Zap!

Bootleg grounds are dangerous.