CAPS-720 is a 100-240 VAC power supply for the Campus-RS Star. Power supplies provide power to the Campus-RS Star chassis and all the installed line units and interface cards. The Campus-RS Star requires connection to one power supply. A second power supply can be used for redundancy to ensure continuous operation in the event of a single power supply failure. If you are only installing one power supply, install it in the center slot on the Campus-RS Star to prevent overheating.