The NAI 44RS1 is a +28VDC IN power line conditioner with holdup capability. The 44RS1 allows the system to automatically switch to 28 VDC Secondary Power whenever 28 VDC Primary Power fails. Upon return of the primary power, the 44RS1 allows the system to use the primary instead of secondary power. The 44RS1 provides 50 milliseconds of Holdup Time (at full power) for power interruption ride through.
Power Supply Reference Guide
Power Supply Configuration Wizard