suojamaadoitusjärjestelmää

Suojamaadoitusjärjestelmä, often referred to as protective earthing, is a crucial safety measure in electrical installations. Its primary purpose is to prevent electric shock by ensuring that conductive parts of electrical equipment that are not normally live are connected to the earth. This connection provides a low-resistance path for electrical current to flow to the ground in the event of a fault, such as insulation failure.

When a fault occurs and a live conductor touches a metal casing of an appliance or piece of equipment, the casing becomes live. Without a protective earth connection, anyone touching this live casing would complete an electrical circuit through their body to the ground, resulting in a potentially fatal electric shock. However, with a suojamaadoitusjärjestelmä in place, the fault current bypasses the person and flows through the earth wire to the grounding electrode, and then into the earth itself.

This large fault current is intended to be sufficient to trip a protective device, such as a fuse or a circuit breaker, thereby disconnecting the power supply to the faulty circuit. This rapid disconnection significantly reduces the risk of prolonged exposure to dangerous voltages. The effectiveness of a suojamaadoitusjärjestelmä relies on the integrity of the earthing conductors and the grounding electrode, as well as the sensitivity and proper functioning of the protective devices. Regular testing and maintenance are essential to ensure the system remains effective.