Pienjännitesuojelussa

Pienjännitesuojelussa refers to the protection against low voltage in electrical systems. This is a crucial aspect of electrical safety, designed to prevent harm to people and damage to equipment caused by low voltage faults or indirect contact. Low voltage, as defined by various electrical standards, typically ranges from 50V to 1000V AC or 120V to 1500V DC, though specific definitions can vary by region and application.

The primary goal of pienjännitesuojelussa is to ensure that the voltage a person might be exposed to during a fault condition remains at a safe level. This is achieved through various protective measures, including protective earthing, protective insulation, protective separation, and the use of safety extra-low voltage (SELV) or protective extra-low voltage (PELV) systems. Protective earthing involves connecting exposed conductive parts of electrical equipment to the earth, so that in case of a fault, the fault current flows to the ground, and protective devices like circuit breakers or fuses can quickly disconnect the power supply. Protective insulation involves using materials that prevent the passage of electricity, thus isolating live parts from accessible surfaces.

Protective separation is used to isolate a circuit from earth by means of a special transformer, ensuring that if a fault occurs, the voltage to earth remains very low. SELV and PELV systems operate at voltages so low that they are considered inherently safe under normal conditions. The implementation of pienjännitesuojelussa is mandated by electrical safety regulations and standards, and its correct application is essential for preventing electric shock and fires. Regular inspection and maintenance of these protective measures are also vital to ensure their continued effectiveness.