Changeover Switch is electrical switchgear which switches a load between two power sources. ON Load Changeover Switch consists of two separate sets of terminals for incoming supplies & a set of output terminals to connect the common load. Generally, it has three stable positions, ON-I: Load is connected to the Source 1 or primary supply ; ON-II: Load is connected to Source 2 or back-up supply ; OFF: Load is isolated from both Sources. Manual Changeover Switch is operated by hand manually.