Eaton 9E Installation And Operation Manual

Also see for 93E: User and installation guide Operation manual Installation and operation manual Installation and operation manual Instructions

Contents

Understanding UPS Operation5-2 Eaton 9E UPS (80-200 kVA, 380/400/415V) Installation and Operation ManualA single UPS operates independently to support an applied load from the inverter, providing conditioned anduninterruptible AC power to the critical load from the output of the module. During an outage, the invertercontinues to operate, supporting power to the load from the battery supply. If the unit requires service, appliedloads are transferred to the internal bypass either automatically or manually. With the exception of an optionalexternal battery cabinet, no other cabinets or equipment are required for the single UPS to successfully supportits applied loads.5.2.1 ModesThe Eaton 9E UPS supports a critical load in four different modes of operation:• In Standard 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, if needed,Standard mode is the standard normal operating mode.• In High-Efficiency (HE) mode, commercial AC power is supplied directly to the critical load through theinternal bypass and transfers automatically to Standard Normal mode (double-conversion on demand) if anabnormal condition is detected.• In Bypass mode, the critical load is directly supported by utility power.• In Battery mode, the battery provides DC power, which maintains inverter operation. The battery supportsthe critical load.The following paragraphs describe the differences in the UPS operating modes, using block diagrams to showthe power flow during each mode of operation.5.2.2 Standard Normal ModeDuring Standard Normal mode, power for the system is derived from a utility input source through the rectifierinput contactor. Three-phase AC input power is converted to DC using IGBT devices to produce a regulated DCvoltage to the inverter. When the battery contactor is closed the battery is charged directly from the regulatedrectifier output through a buck or boost DC converter, depending on the system voltage and the size of thebattery string attached to the unit.Figure 5-2 shows the path of electrical power through the UPS system when the UPS is operating in Normalmode.The battery converter derives its input from the regulated DC output of the rectifier and provides either aboosted or bucked regulated DC voltage charge current to the battery. The battery is always connected to theUPS and ready to support the inverter should the utility input become unavailable.The inverter produces a three-phase AC output to a customer's load without the use of a transformer. Theinverter derives regulated DC from the rectifier and uses IGBT devices and pulse-width modulation (PWM) toproduce a regulated and filtered AC output. The AC output of the inverter is delivered to the system outputthrough the output contactor.5.2 Single UPSIf the utility AC power is interrupted or is out of specification, the UPS automatically switches to Battery modeto support the critical load without interruption. When utility power returns, the UPS returns to Normal mode.