berøringsspænding

Berøringsspænding, also known as touch voltage, refers to the electrical potential difference that a person or animal might experience when touching an energized object and simultaneously being in contact with the ground or another conductive surface. This voltage arises from the flow of fault current through the earth or other conductive materials. If a fault occurs, such as a live wire touching a metal enclosure that is not properly earthed, a voltage will appear on the enclosure. If a person then touches this enclosure while standing on the ground, a path for the fault current is created through their body.

The magnitude of the berøringsspænding depends on several factors, including the magnitude of the fault current, the resistance of the ground, the resistance of the person's footwear and body, and the distance from the fault to the point of contact. Higher fault currents and higher ground resistances generally lead to higher touch voltages. This phenomenon is a critical safety consideration in electrical installations, as excessive touch voltages can cause electric shock, leading to muscle contractions, burns, and potentially cardiac arrest. Protective measures, such as earthing (grounding) systems and residual current devices (RCDs), are designed to limit the duration and magnitude of touch voltages, thereby reducing the risk of injury.