Removed from a working environment. The APC AP7721 is a rack-mounted Automatic Transfer Switch (ATS) designed to provide redundant power to equipment that only has a single power supply input. It is commonly used in server racks, network cabinets, and data centres. The AP7721 has two power inputs (Source A and Source B) connected to separate power feeds or UPS systems. If the preferred power source fails, the AP7721 automatically switches the connected equipment to the alternate source with virtually no interruption. This allows single-corded devices to benefit from dual power feeds. Current monitoring and overload alarms. Event logging and notifications.