“What is a ground wire?” is a common question posed by homeowners and other do-it-yourself types working on their first electrical repair or upgrade project. However, it is a critical piece of knowledge that needs to be fully understood in order to provide protection against electrocution, fire and other issues that can result from not installing an appliance or electrical fixture correctly. Ground wires may not always be readily recognized, and they are critical for the safe use of non-shielded electrical equipment that plugs into a receptacle.
Ground Wires Are a Safety Feature
The ground wire of electrical outlets and house wiring is an alternative path for electricity to flow through in the event of a failure or electrical fault inside an electrical appliance or fixture. Think about your metal clothes washer. Inside the washer there are electrical connections to the timer, motor and other components. Each carries the potential for full household AC electricity that can generate enough of a shock to stop a heart or cause serious burns, or arcing that can cause a fire.
How Ground Wires Work
If a hot wire inside your clothes washer breaks loose and comes in contact with the metal shell, nothing will happen if it is not grounded and if there is no complete circuit. However, touching the washer can turn your arm into the conductor that completes the electrical circuit. If you have one hand on the washer and lean over and touch the faucet on a sink or another object that can conduct electricity, the current will flow right across your heart and most likely kill you. Electricity can conduct through your feet even if you are wearing shoes.
Ground wires connect to the metal housing and other metal components. They follow a path back through the third wire on the power cord and into an electrical outlet through that third prong on the plug. They go all the way back to the breaker box and into the actual earth ground rod outside your home. This becomes the primary route electricity will travel if there is a problem rather than it going through you. Electricity always takes the path of least resistance. Ground wires also make is so breakers will trip as soon as a fault occurs.
Ground Wires in Outlets and Fixtures
Older homes often have receptacles with plugs that cannot take a standard three-prong plug. These outlets lack a ground wire. Installing a three-prong plug does not mean the system is grounded. The actual wires that lead back to the service panel must have three conductors. Typical 120 volt household circuits have a hot wire (black), white wire (neutral return) and a bare conductor (ground). The ground is the alternate, or safety path, for electricity to flow if there is a problem.
Ceiling light fixtures, medicine cabinet light bars, ceiling fans and other permanently wired fixtures and appliances that run off of standard household current have ground wires in the fixtures/appliances that need to be connected by a wire nut to the bare ground conductor of the power cable. Metal work boxes used to hold receptacles, lights, fans and other fixtures/appliances also need to be grounded.
Trust Mister Sparky for all Electrical Repairs
Here at Mister Sparky, our highly trained electricians know how to install any electrical appliance or fixture to meet National Electric Code compliance for consumer safety. Got an electrical project? Please give us a call or contact us online so one of our electricians can hook up that new fixture or appliance for you.