A "power changeover device" allows for the transfer of power from one source to another. Synonyms for this term include "transfer switch", "transfer unit", and "power selector switch". These devices are commonly used in situations where a backup power source, such as a generator, is needed in the event of a power outage. Other words that can be used to describe these devices include "power switching device", "power switching unit", and "power failure protection system". Whatever the name may be, a power changeover device is essential for maintaining uninterrupted power supply in critical applications.