Emerson 250-400kVA manual Input Power Failure-Load on Battery, Input power fail, load on battery

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Operation

2.3.3Input Power Failure—Load on Battery

If the utility AC power source fails or is outside the acceptable range, the battery plant becomes the power source for the UPS module inverters. The UPS continues to supply power to the critical load and also to the UPS controls.

Use the Battery Time screen at the UPS modules to monitor the present battery voltage compared to the shutdown value. The time the battery can sustain the load depends on the size of the load and the size and condition of the battery plant.

Alarm messages that indicate battery status are Battery Discharge, Low Battery and Battery Shut- down. The voltage limits for these alarms are displayed on the UPS module Alarm Limit Settings screen. These limits were selected for your installation by Liebert Services during initial startup. The battery block in the UPS module Monitor/Mimic Display indicates Charge or Discharge and the cur- rent in amperes.

Figure 26 Input power fail, load on battery

Bypass

BFB

Input	DC Bus
CB1	CB2

Module Output

Battery System

MBD

21

Image 27

Contents Liebert NXL Contacting Liebert for Support Battery Cabinet PrecautionsTable of Contents Specifications Figures Page Important Safety Instructions Normal Mode General DescriptionModes of Operation Options Bypass ModeBattery Mode Maintenance BypassIntroduction Main component locations FeaturesMimic display Monitor/mimic display example Utility fail Monitor/mimic display example Normal power flowMonitor/mimic display example Load on bypass, UPS On Menu tree Touchscreen Navigation Main Display ScreenRating Parameters Configurations Menu RatingSystem Settings parameters User SettingsAdjustable setpoints parameters Adjustable SetpointsCell Count Adjustment Event Management Status Reports MenuStartup Menu Shutdown menu Shutdown MenuTransfer Menu Transfer/retransfer commandsTime remaining display Battery Management MenuDisplay summary see Figure Silence ResetMetering HelpLoad on bypass, UPS available OK to TransferInput power fail, load on battery Input Power Failure-Load on BatteryEmergency Module Off Off BatteryRemote Emergency Power Off Manual ProceduresStartup Procedure Startup commands Maintenance Bypass Load Transfers Load Transfer ProceduresTransfer Procedure Re-Transfer ProcedureMaintenance Bypass Load Transfers-If Load is on UPS Bypass Automatic Operations Shutdown ProceduresUPS Shutdown Procedure System Shutdown ProcedureCurrent-versus-time curves of overload capacity Automatic Transfers to Bypass Overload ConditionAutomatic Retransfers to UPS Automatic Transfers to Bypass, UPS System FaultsSafety Precautions Routine Maintenance Liebert ServicesAir Filters Record LogComponent Expected Life Replace Battery MaintenanceUPS component service life Limited Life ComponentsBattery Safety Precautions Matching Battery Cabinets-Optional Battery voltage, nominal and floatBattery retorque values Torque Requirements Torque specifications, unless otherwise labeledDetecting Trouble Rack-Mounted BatteriesReporting a Problem Upstream Feeder Circuit Breaker Setting InspectionsCorrective Actions Environmental Conditions Battery OperationEnvironmental specifications Parameter SpecificationInput Parameters Electrical specificationsBattery & DC Parameters Liebert NXL Model Size 250Liebert NXL Model Size System ParameterPhysical Parameters & Standards, in mm Specifications Event Message Event Definition Recommended Action Liebert NXL alarm and status messagesObserve the One-Line Display. If the input line is Observe the One-Line Display. To identify which Do not Attempt to Close CB3 Until Reset Displayed on the Module Output Meter. If UPS controls monitor the DC Bus positive Resolve the issue that precipitated the EPO Check the One-Line Display for system status UPS, to transfer back to Inverter If this alarm occurs on an operational unit, it Attempt to manually close the disconnect by Module Output Meter. If the load is less than Output Power Factor. If the displayed power factor Until a service visit has been made and action taken When manual transfers are enabled Under normal conditions, no user action is required Observe the One-Line Display and the Active Event If the command to terminate Regeneration Mode If the alarm cannot be reset, or if the alarm condition UPS Alarm and Status Messages UPS Alarm and Status Messages Page That Ne tIti Ti n