Vaihtokytkentä

Vaihtokytkentä, a Finnish term, translates to "changeover switch" or "transfer switch" in English. It refers to a type of electrical switch that connects a load to one of two possible power sources. This is commonly used to ensure continuity of power supply in situations where a primary source might fail or when a facility needs to switch between different power grids or generators.

The primary function of a vaihtokytkentä is to select between two inputs and direct one of them to a single output. In simpler terms, it allows a device or system to run on either the main power line or a backup power source, such as a generator or an uninterruptible power supply (UPS). This switching can be manual, where an operator physically changes the switch position, or automatic, where the switch senses a power failure and transfers the load to the backup source without human intervention.

Automatic changeover switches are particularly important in critical applications like hospitals, data centers, and telecommunication facilities where even brief power interruptions can have severe consequences. They incorporate control logic that monitors the status of the primary power source. If the primary power is lost or falls outside acceptable voltage or frequency parameters, the automatic switch disconnects the load from the primary source and connects it to the secondary source. Once the primary power is restored and stable, the switch can be configured to automatically transfer the load back.

The design of a vaihtokytkentä varies depending on its application and the power ratings involved. They can range from simple, manually operated rotary switches to sophisticated, electrically controlled units with advanced monitoring and protection features. The core principle remains the same: providing a reliable mechanism to select between alternative power supplies for a connected load.