P-164000476 9395P 500kVA / 600 kVA 62Revision 002 User’s and Installation Guide6.2 Single UPSA single UPS operates independently to support an applied load from the inverter, providingconditioned and uninterruptible AC power to the critical load from the output of the module. During anoutage, the inverter continues to operate, supporting power to the load from the battery supply. If theunit requires service, applied loads are transferred to the internal bypass via the continuous-duty staticswitch either automatically or manually. With the exception of a battery cabinet, no other cabinets orequipment are required for the single UPS to successfully support its applied loads.6.2.1 ModesThe Eaton 9395 UPS supports a critical load in five different modes of operation. The UPS canautomatically use all five modes, as required.NOTEThe Variable Module Management System and Energy Saver System modes are mutuallyexclusive.The standard operation modes are:• In Normal mode, the critical load is supplied by the inverter, which derives its power from rectifiedutility AC power. In this mode, the battery charger also provides charging current for the battery, ifneeded.• In Battery mode, the battery provides DC power, which maintains inverter operation. The batterysupports the critical load.• In Bypass mode, the critical load is directly supported by utility power.• In Variable Module Management System (VMMS) mode, the UPS operates as a traditional double-conversion UPS, but selectively shifts the load to fewer UPMs to increase the efficiency of theUPS.• In Energy Saver System (ESS) mode, the critical load is directly supported by utility power, but withthe ability to automatically switch to Normal mode if an abnormal condition is detected.The following sections describe the differences in the five UPS operating modes, using block diagramsto show the power flow during each mode of operation.6.2.2 Normal modeFigure 6-2 shows the path of electrical power through the UPS system when the UPS is operating innormal mode.NOTEOn a UPS configured as an IOM, the bypass input, static switch, and K5 are not present.
