What is the difference between Bonding, Grounding and Earthing? EEP – Electrical Engineering Portal » What is the how to make earthing pdf between Bonding, Grounding and Earthing?
Share with your Facebook friends! Bonding is more clear word compare to Grounding and Earthing, but there is a micro difference between Grounding and Earhing. Earthing and Grounding are actually different terms for expressing the same concept. We understand that Earthing and Grounding are necessary and have an idea how to do it but we don’t have crystal clear concept for that. In addition, non-current-carrying metallic components in a System, such as equipment cabinets, enclosures, and structural steel, need to be electrically interconnected and earthed properly so voltage potential cannot exist between them. Equipment is earthed to pass fault Current and to trip the protective device without electrifying the device enclosure.
Neutral is the current return path for phase. These Earthing conductor and Neutral conductor are connected together and earthed at the distribution panel and also at the street, but the intent is that no current flow on earthed ground, except during momentary fault conditions. Here we may say that Earthing and grounding are nearly same by practice. Neutral with earth at his premises here earthing and grounding is the different by practice. Let’s try to understand this terminology one by one.
These may be two wires, a wire and a pipe, or these may be two Equipments. Bonding has to be done by connecting of all the metal parts that are not supposed to be carrying current during normal operations to bringing them to the same electrical potential. Bonding ensures that these two things which are bonded will be at the same electrical potential. That means we would not get electricity building up in one equipment or between two different equipment. No current flow can take place between two bonded bodies because they have the same potential.
Bonding itself, does not protect anything. However, if one of those boxes is earthed there can be no electrical energy build-up. If the grounded box is bonded to the other box, the other box is also at zero electrical potential. It protects equipment and person by reducing current flow between pieces of equipment at different potentials. Phase conductor may be touched an external metal part.
The bonding helps to create a low impedance path back to the source. This will force a large current to flow, which in turn will cause the breaker to trip. In other words, bonding is there to allow a breaker to trip and thereby to terminate a fault. Generally green wire is used for this as a nomenclature.
To avoid this non-current carrying metal parts of the electrical system are connected to the general mass of earth by means of an earthing system comprising of earth conductors to conduct the fault currents safely to the ground. Earthing has been accomplished through bonding of a metallic system to earth. It is normally achieved by inserting ground rods or other electrodes deep inside earth. Earthing is to ensure safety or Protection of electrical equipment and Human by discharging the electrical energy to the earth. It is done for the protections of power system equipment and to provide an effective return path from the machine to the power source. For example grounding of neutral point of a star connected transformer. Because of lightening, line surges or unintentional contact with other high voltage lines, dangerously high voltages can develop in the electrical distribution system wires.