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Home Electrical System

The Bonded Grounding System

electrical-wiring Summary: Why the Electrical Grounding System is the most important component of the home electrical system.


Grounding the Home Electrical System


Electrical Question: When I worked in a steel mill for 20 years and wanted to revise some old outlets at home to grounded outlets, since I was a millwright, some of the industrial electricians taught me what was supposed to be an easy fix.

They told me to install the new outlet with the 3 prong receptacle for the ground plug, but to add a ground wire from the neutral to ground on the outlet and I won't have to rerun all the wiring from the box.

  • This seemed like about 100 hours of work saved in addition to money, so I tried it out on one and plugged in a tester you buy at the building supply and it showed a perfect ground with all the lights working perfectly on the tester. I was happy so I did them all. I relocated to another state and in the old house I bought I wanted to do the same thing of adding a grounded receptacle, so I asked a local electrician who wanted an enormous amount of money claiming he'd have to re-run hundreds of feet of wire and fish it all through the walls, so I opted for the old method taught to me by the industrial electricians.
  • I did them all and bought a newer tester to make sure it was up to date and again it worked just fine. When the local electrical guy came along and asked about it, I told him what I did and he very loudly claimed it won't work, they have to be grounded by wire from the box. He didn't believe that it worked, so he plugged in a tester and it showed a perfect ground so he said they will penalize me if the city finds out because it's not a ground.
  • So, I drew it all out on paper and even though the ground connection was jumped from the ground screw to the neutral screw, it still worked on paper to achieve a ground with the simple difference of doing it at the outlet other than the box. Do I have to unlearn what I learned a long time ago or should I never tell anyone what I did? FROM: A disabled veteran in Ohio, who wanted to save a lot of bucks.
Dave's Reply:
I must say - I had to smile a little while reading your comment, because I have had several conversations about this very same issue and concern. I might add that I have discovered countless receptacles during renovations where this method was installed, needless to say the wiring was upgraded and grounded cable was installed.

  • The Difference Between Ground and Neutral Wires Without getting theoretical, a neutral wire has insulation covering the conductor because there is not only voltage that is present, there is in most cases current or amperage flow as well. If a clamp on amp meter was placed around a neutral wire of a 120 volt circuit that was in use you would see current flow, in fact if a 120/240 volt electrical service were to ever become unbalanced it could overheat the neutral wire to the point of overheating and possibly cause a fire. So the point here is that the neutral wire is a vital part of a 120 volt alternating circuit, as well as other commercial and industrial voltages such as 277 volts etc..
  • Now that you have this understanding and you think about the illegal method of looping the neutral wire to the ground screw of an outlet you may now be aware that this method has the potential of placing any portion of the return voltage and potential current to the ground prong of the receptacle outlet and worse, any device that is plugged into the outlet. Now for the Real Electrical Hazard Imagine that this illegal method of grounding is in place, and a person plugs in a 3-wire appliance that has a ground wire, and the outer frame or enclosure of the appliance is metallic and this enclosure is bonded to the ground wire of the appliance, as it should be because it does have a ground wire to provide that measure of safety. Well think of what would happen if the person that is using the appliance comes into contact with a source or path to ground, can you see what is about to happen, This should actually send chills down your spine because the person now has the potential of becoming a human conductor of any residual electrical voltage and electrical current that is passing from the neutral wire of that entire electrical circuit to the earth ground source.
  • The same is true if the appliance has an internal voltage leak or faulty component that is sending voltage to what should be the ground system of the circuit, but if the circuit ground path is not available but the person is in contact with a grounded source then they have the potential of becoming a human conductor of electricity and receiving a electric shock. The Behavior of Electricity The important thing about electricity is that it is attracted to any earth ground source, and it does not matter what the source is. This is very evident when i see the damage that occurs when a home has been stuck by lightning.
  • The energy of lighting has the potential of frying anything and everything in its path on the way to any sources of ground. Granted, lightning strikes contain extremely high voltage, but the concept is exactly the same.
  • The Function of a Earth Ground System You will notice that the typical 2-wire cable with a ground is made up of two insulated wire conductors and with most NM cables the ground is bare, or uninsulated. The ground wire is uninsulated because it is not used as a current carrying conductor. The purpose of the ground wire is to provide a direct bonded low resistance path to earth ground.
  • If a circuit component encounters a problem and the circuit components are properly grounded the ground wire is available to direct voltage and current to the earth ground which by design will cause over current devices on the circuit to react and interrupt the source of electricity, such as GFCI devices, circuit breakers and fuses.
  • The function of a earth ground system is to protect the electrical system components, and also drain electrical line disturbances to the ground. The function of a GFCI Ground Fault Circuit Interrupter is to help prevent electrical shock and interrupt the circuit or trip it off. As mentioned above, the neutral wire is a vital part of an electrical circuit, and should never be used as a ground wire.
  • There is only one place where the neutral and ground meet and that is at the main electrical panel where the main ground source now provides the path to ground. So Dan, how valuable is human life compared to saving some money? Sure i know, times are definitely tough on all of us right now, but I'd rather not see how you look with a fro or worse. I would encourage you to make the corrections, and by all means ask for help from folks in your community. I am extremely grateful to all of you fine people who have served our country, and that';s just one reason why I try to help people out with this website.
  • One Solution On the Practical Side You may legally install 3-prong GFCI outlets without a ground wire as long as a special label is placed on the receptacle indicating that there is not a ground available. This is ideal in areas such as the kitchen, bathroom, garage, basement and outdoors where there is an outlet that is near a grounded source such as a facet. The GFCI will still work by interrupting the circuit if it senses a current leak.
    I hope this helps! Dave

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