Changeover switch

A changeover switch is a manual or automatic switching device used in some battery-backup installations to transfer backed-up circuits, a backed-up consumer unit or a whole-property backup arrangement between the normal grid supply and the system's backup or EPS output. In island-mode storage guidance, the maintained circuits have to be disconnected from the grid supply before the battery system supplies them. A manual changeover switch needs user action, while an automatic changeover switch or relay changes supply without the householder operating the switch. The switch does not create backup capability by itself: backup still depends on the installed EPS or backup hardware, isolation arrangement, earthing, inverter output, battery state of charge, circuit design and loads connected at the time.