Keskusmaadoitus

Keskusmaadoitus, also known as central earthing or main earthing, is a crucial electrical safety concept and practice. It refers to the connection point where the protective earthing conductors of an electrical installation are brought together and connected to the main earthing terminal. This main earthing terminal is then bonded to the general mass of earth, typically through an earth electrode.

The primary purpose of keskusmaadoitus is to ensure that all exposed conductive parts of an electrical installation are at the same electrical potential. In the event of a fault, such as a live conductor coming into contact with a metal casing, the fault current is directed through the earthing system back to the source of supply, causing protective devices like circuit breakers or fuses to operate and disconnect the power. This prevents dangerous voltages from appearing on accessible surfaces, thereby protecting people from electric shock.

The keskusmaadoitus system is a fundamental part of a TN or TT earthing system, which are common types of electrical distribution configurations. It ensures that the effectiveness of the earthing is maintained throughout the entire installation. Proper installation and maintenance of the keskusmaadoitus are vital for the overall safety and reliability of the electrical system. It is designed to provide a low-impedance path for fault currents, facilitating prompt disconnection of the faulty circuit.