Emerson 250-400kVA manual General Description, Modes of Operation, Normal Mode

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Introduction

1.0INTRODUCTION

1.1General Description

The Liebert NXL UPS provides continuous, high-quality AC power to your business-critical equip- ment, such as telecommunications and data processing equipment. The Liebert NXL UPS supplies power that is free of the disturbances and variations in voltage and frequency common to utility power, which is subject to brownouts, blackouts, surges and sags.

The Liebert NXL utilizes the latest in high-frequency, double-conversion pulse-width modulation technology and fully digital controls to enhance its reliability and increase the ease of use.

As shown in Figure 1, the AC utility source is input at CB1 and the rectifier converts the AC utility into DC power. The inverter converts that DC power from the utility—or DC power from the batter- ies— into AC power for the load. The batteries power the load through the inverter in the event of a power failure. The utility source can also power the load through the static bypass.

If maintenance or repair of the UPS is necessary, the load can be switched without interruption in service to the maintenance bypass.

Figure 1 Typical UPS system one-line diagram

Bypass

BFB

Input

CB1

Battery

System

1.2Modes of Operation

1.2.1Normal Mode

DC Bus

CB2

MBD

Module Output

Operating in normal mode, the Liebert NXL’s rectifier derives power from a utility AC source and supplies regulated DC power to the inverter, which regenerates precise AC power to supply the con- nected equipment. The rectifier also uses the utility source power to charge the batteries.

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Contents Liebert NXL Battery Cabinet Precautions Contacting Liebert for SupportTable of Contents Specifications Figures Page Important Safety Instructions Modes of Operation Normal ModeGeneral Description Bypass Mode Battery ModeMaintenance Bypass OptionsIntroduction Features Main component locationsMimic display Monitor/mimic display example Normal power flow Monitor/mimic display example Utility failMonitor/mimic display example Load on bypass, UPS On Touchscreen Navigation Main Display Screen Menu treeConfigurations Menu Rating Rating ParametersUser Settings System Settings parametersAdjustable Setpoints Adjustable setpoints parametersCell Count Adjustment Startup Menu Event ManagementStatus Reports Menu Shutdown Menu Shutdown menuTransfer/retransfer commands Transfer MenuBattery Management Menu Time remaining displayDisplay summary see Figure Reset MeteringHelp SilenceOK to Transfer Load on bypass, UPS availableInput Power Failure-Load on Battery Input power fail, load on batteryOff Battery Emergency Module OffManual Procedures Remote Emergency Power OffStartup Procedure Startup commands Load Transfer Procedures Transfer ProcedureRe-Transfer Procedure Maintenance Bypass Load TransfersMaintenance Bypass Load Transfers-If Load is on UPS Bypass Shutdown Procedures UPS Shutdown ProcedureSystem Shutdown Procedure Automatic OperationsAutomatic Transfers to Bypass Overload Condition Current-versus-time curves of overload capacityAutomatic Transfers to Bypass, UPS System Faults Automatic Retransfers to UPSSafety Precautions Liebert Services Routine MaintenanceRecord Log Air FiltersBattery Maintenance UPS component service lifeLimited Life Components Component Expected Life ReplaceBattery Safety Precautions Battery retorque values Matching Battery Cabinets-OptionalBattery voltage, nominal and float Torque specifications, unless otherwise labeled Detecting TroubleRack-Mounted Batteries Torque RequirementsCorrective Actions Reporting a ProblemUpstream Feeder Circuit Breaker Setting Inspections Battery Operation Environmental specificationsParameter Specification Environmental ConditionsElectrical specifications Battery & DC ParametersLiebert NXL Model Size 250 Input ParametersPhysical Parameters & Standards, in mm Liebert NXL Model SizeSystem Parameter Specifications Liebert NXL alarm and status messages Event Message Event Definition Recommended ActionObserve 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 Ne t ItiTi n That