Earthing provides a low impedance ground path for power if an insult fails and a live cable comes into contact with an exposed part of a device, causing the device to be live and potentially dangerous to use. Ground is also used to provide a neutral line reference voltage in most AC distribution systems and a zero voltage for DC distribution systems.
As a precaution, modern safety switches for residual current circuit breakers reduce the need for Earthing by comparing the difference between the current flowing on the active and the neutral line and switching off the power to the active current if they differ only by a few milliamperes. The current in the active and neutral lines should always be the same, unless the circuit is broken.
Why is earthing required?
Grounding is the process of conducting excess current through the enclosure of an electrical device. This is done for safety reasons to avoid personal injury.
Why is ground earthing needed?
Earthing, also known as grounding, is a crucial electrical safety measure used in electrical systems and installations. It involves connecting electrical equipment and devices to the Earth’s conductive surface, typically through metal conductors such as copper or aluminum.
The primary reasons why earthing is required are:
1. Electrical Safety: Earthing provides a path of least resistance for the flow of excess electrical current. If a fault occurs in an electrical system, such as a short circuit or a ground fault, the excess current is directed towards the ground through the earthing system. This helps to prevent electric shocks, fires, and damage to equipment by effectively dissipating the fault current.
2. Personal Safety: When electrical equipment is properly grounded, it reduces the risk of electric shock to individuals. If a fault occurs and a live wire comes into contact with a conductive surface that is grounded, such as a metal appliance casing, the fault current will flow through the grounding system instead of passing through a person who touches the appliance.
3. Surge Protection: Earthing provides protection against electrical surges and transient voltage spikes. Surges can occur due to lightning strikes, power grid fluctuations, or the operation of large machinery. By providing a low-impedance path to the ground, earthing helps to divert excessive voltage away from sensitive electronic devices and appliances, preventing damage to them.
4. Static Electricity Dissipation: In certain environments, such as manufacturing plants or laboratories, static electricity can build up on objects or equipment. Earthing helps to dissipate static charges, preventing the accumulation of electric potential and reducing the risk of electrostatic discharge (ESD) that can damage sensitive electronic components or ignite flammable substances.
5. Electromagnetic Interference (EMI) Reduction: Electrical systems can generate electromagnetic fields that may interfere with the proper functioning of nearby electronic devices. Proper earthing helps to minimize these electromagnetic interferences by providing a reference potential and reducing the potential difference between grounded objects.
Overall, earthing is essential for electrical safety, personal protection, equipment protection, and the prevention of electrical hazards. It ensures that electrical faults are handled safely and reduces the risk of electric shocks, fires, damage to equipment, and disruption to electronic systems.