UNDERSTANDING UPS OPERATIONEATON Eaton 9395 550/275 UPS (225–550 kVA) Installation and Operation Manual 164201716 Rev 2 www.eaton.com/powerquality6-18If at any time during the battery discharge the input power becomes available again,the rectifier begins to supply DC current to the inverter. At this point, the UPS returnsto Online mode. If at any time during the battery discharge the AC input powerbecomes available again, each rectifier turns on, assumes the inverter load from thebatteries, and begins recharging the batteries. Depending on the total load and theduration of the battery discharge, battery and rectifier input current limit alarms maybe seen for a short time due to the current required to recharge the batteries.6.5 Multiple UPS Distributed Bypass System Oneline ConfigurationsThe distributed bypass system oneline drawings in this section show the simplifiedinternal structure of the UPS, battery supply, and basic maintenance bypass in amultiple UPS configuration. These onelines do not show each UPM in the UPSs, butrepresent each UPS in the distributed bypass system. The internal structure of eachUPS is shown in Figure 6‐5 through Figure 6‐8 starting on page 6-8.Oneline Drawing UPS ModelVoltageSystem TypeInput OutputFigure 6‐13 on page 6-199395-550/2259395-550/2759395-550/4509395-550/5009395-550/550400480400480Multiple UPS – Distributed Bypass1+1 and 2+0 ConfigurationsFigure 6‐14 on page 6-209395-550/2259395-550/2759395-550/4509395-550/5009395-550/550400480400480Multiple UPS – Distributed Bypass2+1 and 3+0 ConfigurationsFigure 6‐15 on page 6-219395-550/2259395-550/2759395-550/4509395-550/5009395-550/550400480400480Multiple UPS – Distributed Bypass3+1 and 4+0 Configurations
