Kosketusjännitteissä

Kosketusjännitteissä is a Finnish term that translates to "touch voltages" in English. It refers to the electrical potential difference that can exist between two points that a person might simultaneously touch during an electrical fault or malfunction. When an electrical fault occurs, such as a live wire coming into contact with a conductive surface like a metal casing or the ground, a voltage can be present on that surface. If a person then touches this energized surface and simultaneously touches another point that is at a different electrical potential (e.g., another conductive surface, the ground, or a properly grounded object), they will experience a touch voltage.

The magnitude of the touch voltage depends on several factors, including the fault current, the resistance of the earth or ground connection, and the resistance of the person's body and footwear. Higher touch voltages pose a greater risk of electric shock, which can cause muscle contractions, burns, and even cardiac arrest. Safety regulations and standards, such as those governing electrical installations and equipment, aim to limit touch voltages to safe levels to protect individuals from these hazards. This is often achieved through protective measures like proper grounding, insulation, and protective devices such as residual current devices (RCDs). Understanding touch voltages is crucial for electrical safety and designing and maintaining safe electrical systems.