Überspannung

Überspannung refers to a transient overvoltage that significantly exceeds the normal operating voltage of an electrical system. These events are typically very short-lived, lasting from microseconds to milliseconds. Überspannung can be caused by a variety of factors, both external and internal to a system.

External causes are most commonly associated with lightning strikes. A direct lightning strike can induce massive voltage surges in electrical conductors, even if the strike does not hit the system directly. Nearby lightning strikes can also induce significant overvoltages through electromagnetic induction. Another significant external cause is the switching of heavy electrical loads on the power grid. When large inductive or capacitive loads are connected or disconnected, the sudden change in current can generate voltage spikes.

Internal causes of Überspannung include the switching of electrical equipment within a facility, such as motors, transformers, or capacitors. These internal switching transients are generally of lower magnitude than lightning-induced surges but can still be damaging over time. Poor grounding or faulty wiring can also contribute to the occurrence and severity of Überspannung events.

The consequences of Überspannung can range from minor malfunctions to catastrophic failure of electronic and electrical equipment. Sensitive electronic components, such as microprocessors and integrated circuits, are particularly vulnerable to damage from even short-duration overvoltages. This can lead to data loss, system crashes, and premature equipment failure. To mitigate the risks associated with Überspannung, protective devices like surge arresters and transient voltage suppressors are commonly installed in electrical systems and at the point of use for sensitive equipment.