Ylijännitesuojalaitteilla

Ylijännitesuojalaitteilla, often abbreviated as YVS or SPD (Surge Protective Device), are electrical devices designed to protect electrical equipment from transient overvoltages. These overvoltages can be caused by various sources, including lightning strikes, switching operations within the power grid, and faults in the electrical system. When a surge occurs, the ylijännitesuojalaitteilla diverts the excess voltage away from the sensitive equipment, thereby preventing damage.

The primary function of a ylijännitesuojalaitteilla is to limit the voltage to a safe level. They typically contain components like Metal Oxide Varistors (MOVs) or gas discharge tubes (GDTs) that exhibit a non-linear resistance. Under normal operating voltages, these components have very high resistance, allowing electricity to flow to the protected equipment without interruption. However, when a voltage surge occurs, their resistance drops dramatically, creating a low-impedance path that shunts the excess current to ground. Once the surge has passed and the voltage returns to normal, the resistance of the protective component increases again, and normal operation resumes.

Ylijännitesuojalaitteilla are commonly installed in electrical panels, at the service entrance of buildings, and directly on sensitive electronic devices. They are crucial for safeguarding computers, televisions, industrial machinery, and other valuable equipment from the damaging effects of voltage spikes, extending their lifespan and ensuring reliable operation. The selection of an appropriate ylijännitesuojalaitteilla depends on factors such as the voltage level of the system, the expected surge currents, and the sensitivity of the equipment being protected.