Electrical bonding in buildings
– Metal objects in buildings are connected to the mains earth for safety reasons.
– TN−C−S earthing system is commonly used in the UK, where the neutral and earth conductors are combined.
– Bonding is done to prevent electric shock hazards if the ground connection to the neutral is lost.
– Examples of bonded articles include metallic water piping systems, gas piping, and exposed metal parts of buildings.
– Bonding ensures that all metal objects in the building are at the same potential, reducing the risk of electric shock.
Earth protection
– Grounding non-current-carrying metal parts of equipment diverts current due to faults to earth.
– In a TN system, earthing allows rapid detection and interruption of circuit faults.
– In a TT system, an RCD is used for disconnection in case of faults.
– RCDs are also used to rapidly disconnect small earth faults in various situations.
– Earth protection helps prevent electrical accidents and damage to equipment.
Equipotential bonding
– Equipotential bonding involves connecting metalwork to ensure the same voltage everywhere.
– Exact rules for electrical installations vary by country, locality, or power company.
– Bonding is done from the distribution wiring entry point to incoming water and gas services.
– Bathrooms require bonding of all exposed metal and electrical circuit earths.
– Isolated metal objects are not required to be bonded, except in specific construction cases.
Aircraft electrical bonding
– Electrical bonding in aircraft prevents static electricity build-up that can interfere with equipment.
– Bonding provides lightning protection by allowing current to pass through the airframe.
– It also prevents dangerous static discharges in fuel tanks and hoses.
– Bonding is crucial for safety and proper functioning of aircraft systems.
– It helps ensure reliable communication and navigation in flight.
Related topics and additional information
– Earthing system: Related topic on grounding electrical systems.
– Earth potential rise: Phenomenon associated with electrical grounding.
– Stray voltage: Unintended voltage present in electrical systems.
– Bonding jumper: Device used to connect two conductive objects.
– Notes and references: Additional sources and information on electrical bonding. Source: https://en.wikipedia.org/wiki/Electrical_bonding
Electrical bonding is the practice of intentionally electrically connecting all exposed metal items not designed to carry electricity in a room or building as protection from electric shock. Bonding is also used to minimize electrical arcing between metal surfaces with electrical potential differences. If a failure of electrical insulation occurs, all bonded metal objects in the room will have substantially the same electrical potential, so that an occupant of the room cannot touch two objects with significantly different potentials. Even if the connection to a distant earth is lost, the occupant will be protected from dangerous potential differences.
