INTRODUCTIONPower Xpert 9395 Plus 1 UPS (225–275 kVA) Installation and Operation Manual 164201710 Rev 7 www.eaton.com/powerquality 1-5The tie cabinet must contain Module Output Breakers (MOBs) with dual auxiliarycontacts for control of the system. Without dual auxiliary MOBs, UPMs are notallowed to go to bypass individually during servicing. All UPMs will go to bypassinstead of just the UPM needing service, decreasing critical load protection. With dualauxiliary MOBs, one UPM can be bypassed while the remaining UPMs support theload as long as the remaining UPMs have the capacity to do so.1.2.8 Inherent RedundancyTo deliver greater reliability, the Power Xpert 9395 UPS can be configured by anauthorized Eaton Customer Service Engineer for inherent redundancy. Whenconfigured, the UPS automatically becomes redundant if the load is at or below thecapacity of the UPMs minus the capacity of one UPM. Under normal conditions theUPMs in the UPS share the load equally. If one or more UPMs becomes unavailableand the load is at or below the capacity of remaining UPMs, the remaining UPMssupply the load instead of transferring to bypass.If the capacity of the UPMs falls below the redundancy level or the load increasesabove redundancy level, but is still able to maintain the load, a loss of redundancyalarm is sounded. If the load exceeds the capacity of remaining UPMs, the UPStransfers to bypass.1.2.9 Energy Saver System and High Alert ModesNOTE Energy Saver System mode requires the UPS to be factory built with a Continuous Static Switch(CSS).NOTE The Variable Module Management System and Energy Saver System modes are mutually exclusive.As a subset of Online mode, the Energy Saver System (ESS)mode maximizesefficiency by eliminating unnecessary power conversion when the commercial powersource is within acceptable voltage and frequency limits. In this mode, the UPS isactively monitoring the critical bus and instantly and seamlessly transitions todouble-conversion mode (inverter online) if a commercial electrical power brownout,blackout, overvoltage, undervoltage, or out‐of‐tolerance frequency condition occurs.In High Alert mode the unit transfers from ESS mode to double-conversion mode or ifin double-conversion mode remains in double-conversion mode for a default timeperiod of one hour. High Alert mode allows the user to place the unit indouble-conversion mode when outside conditions could cause a power disturbance.At the completion of the time period, the unit defaults back to ESS mode. If the HighAlert command is received during the time period, the timer will be restarted.1.2.10 Harmonic Reduction System (HRS)The Harmonic Reduction system mode of the 9395 UPS allows the UPS to activelyreduce the input Total Demand Distortion (TDD) and increase the input power factorwhile maintaining high efficiency operation in ESS mode. The UPS uses one of itsUPMs to perform this active harmonic cancellation.HRS mode uses an extra set of sensors (CTs) on the output bus of the unit. Thesesensors measure the harmonics created by loads attached to the UPS output and thesystem actively reduces these harmonics.NOTE Total Demand Distortion as defined by IEE 519-1992 is the total root-sum-square harmonic currentdistortion, in percent, of the maximum demand load current (the nameplate rating of a fully rated UPS).
