Double power automatic transfer Switches can be operated automatically or manually,the millisecond switching is uninterrupted,the installation and maintenance are convenient. This automatic transfer Switches is used in various occasion where continuous power outages are not allowed,such as homes,shopping mall,factories,laboratories,farm. When the normal power supply is abnormal,the backups power supply works immediately to ensures the continuities,reliability and of the power supply. Working principle:when main power close,it can automatic transfer to generator (generator should on),when main power is restored,it will transfer to main power. The changeover Switches is make of flame retardant component,with excellent insulation,highly temperature resistance.