The primary function of earth wires is to insulate conductors from direct lightning strikes, which can cause line failures (see Chapter 4). Earth wires reduce the risk of damage due to lightning by allowing currents to flow through them. The secondary function of earth wires is to provide a path for current to return to its source after it has passed through another conductor. This is necessary because transmission lines are usually placed at some distance from power substations, and it would be dangerous if they were all to become live before being connected up to the main circuit breaker panel.
Only unbroken or continuous sections of pipe should be used for earth wires. If there are breakers or valves located along the pipe, then each section between them must be broken.
The term "earth" means the ground surface or part of a structure that is at zero potential relative to any other point or part of the structure. In other words, it is the opposite pole of a circuit breaker or fuse box. These are placed near where workers will be working so they do not come into contact with electrical wiring or equipment.
The Function of Earth Wires or Ground Wires in Power Lines Ground wires, also known as earth wires, are bare conductors that are supported on the tops of transmission towers. They protect the line by shielding it and intercepting lightning strikes before they strike the current-carrying conductors below, i.e., power lines. Ground wires do not generally carry current. Instead, they provide an electrical connection back to the tower structure so that any voltage fluctuations on the conductor above will be transmitted through the ground wire and into the supporting structure.
Earth wires are important in high-voltage transmission systems because they prevent electric charges from accumulating on the windings of machinery or on the surface of the conductor. This would happen if there were no ground path available to discharge these accumulated charges. For example, if a large motor was running and its winding became charged, it could cause other parts of the system to malfunction or fail completely if there were no way to release this charge. The solution is to connect the motor winding to a ground point outside of the vehicle using a metal connector called a ground rod, which connects the winding to the surrounding soil. This prevents any charge on the winding from building up enough pressure to blow open a circuit breaker or start a fire.
In low-voltage distribution systems, such as those found within homes, offices, and factories, earth wires are used to protect people from being electrocuted by touching live power lines.
As a precaution, an earth wire is utilized. If there is an accidental leakage of electricity in an electrical equipment with a metallic body, it is transported to the earth through the earth wire and shields the user from an electric shock. Earth wires are also called ground wires or earthing wires.
The term "earth" comes from the Latin word "aurum," meaning "gold." Thus, an earth conductor is a metal rod or wire used to conduct electricity away from energized parts of the wiring system into earth conductor material such as copper or aluminum. The purpose of this is so that people will not be injured by electric shocks from power lines. Power companies use special earth connectors at each end of a cable to connect it to the wiring system. These connectors look like large nuts with eight or more threads per inch. The earth conductor inside the connector attaches to one of these threads.
Electricity always takes the path of least resistance; therefore, if there is a better way to get rid of current than through a resistor or other device that creates heat, then it will do so. The human body is a good example of this. If you touch a live wire, you will get hurt. But if there is a path to earth, then the voltage will travel across your hand and out without harming you. The same thing happens with power cables when they break down.
The overhead earth wire, also known as the ground wire, is a kind of lightning protection that employs a conductor or conductors. It is linked to the transmission line from support to support and is securely grounded at regular intervals. The ground wire deflects direct lightning strikes that might otherwise impact the phase conductors. It also provides a path for current if the cable is hit by lightening to prevent it from flowing through the structure into other parts of the building.
Overhead ground wires must be continuous around each group of supports, and they should be kept as short as possible while still providing adequate distance between them to avoid interference with other services. The minimum size for an earth conductor is 14 AWG, but usually 22 to 24 AWG is used instead. Earth wires are normally black with green or white stripes to make them more visible at night. They can be attached either manually or by equipment mounted on a truck or pole.
Electrical contractors install overhead ground wires when they build or repair power lines. If you see people working on electrical lines above-ground or along road sides, there's a good chance that they're installing overhead ground wires.
You should never attempt to connect your house wiring to an outdoor ground rod because it is not designed to carry electricity. Any connection between your house wiring and an external ground rod will allow electricity to flow into your home even if you're not using any appliances.
Earthing is the process of connecting the metal housing of an electrical device to the ground (at zero potential) via a metal wire known as a "earth wire." It is used as a precautionary measure. The major reason for earthing an electrical item is to avoid electric shock. If electricity enters any object through a conductor such as a copper wire, it will always find a path back to earth through another conductor. If that other conductor is also connected to earth, there will be no current flow and no danger of electric shock.
In general, all household appliances should be earthed if they are not already. Old-fashioned light bulbs do not need connecting to earth because their cases are made of metal. But modern lamps and lights have plastic shells which cannot conduct electricity and so these objects must be earthed. If you are not sure whether an appliance is earthed or not, touch it with a dry piece of cloth and if it gives off a small spark then it is not earthed and needs to be connected to earth.
Electricity is transmitted into buildings by two types of connection: line voltage and circuit voltage. Line voltage is the term used for the voltage appearing on a wired public utility such as a power line from a transformer station. This is usually 120 or 240 volts AC. Circuit voltage is the term used for the voltage between any two points in a circuit containing only resistive loads. This can be either hot/neutral or phase/grounded.