cut off(to turn off an electrical device) verb [UK: kʌt ɒf] [US: ˈkət ˈɒf]
disconnect [disconnected, disconnecting, disconnects](to remove the connection between an appliance and an electrical power source) verb [UK: ˌdɪs.kə.ˈnekt] [US: ˌdɪs.kə.ˈnekt]