American Power Conversion MX28B400 user manual DC Distribution, Battery Management

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4.4. DC Distribution

Distribution is included for up to 24 plug-in circuit breakers. These circuit breakers can be 1 to 100 amps, with 60-100 amp breakers requiring two positions and a circuit breaker adapter kit. When a circuit breaker trips, a normally open switch closes and a CB alarm is reported by the PSCU. To disconnect a load attached to a circuit breaker, move the lever to the down “OFF” position.

NOTE: Circuit breaker alarm contacts close when the circuit breaker is tripped but not when it is turned OFF.

4.5. Battery Management

Battery Charging and Protection

Battery charging and protection are integrated into the power system to support the primary function of providing power to the load. Accurate measurement of battery parameters like voltage, current and temperature are used to maintain and protect the batteries attached to the power plant.

Charging the battery at the correct rate reduces battery heating, increases the charge returned to the battery and prevents excess hydrogen generation or, in the case of VRLA batteries, possible thermal runaway. Battery Maximum Recharge Current is set to the appropriate rate, which is usually based on the size of the battery plant in Ampere-hours.

A typical recharge current setting is battery capacity (abbreviated as “C”) divided by number of charging hours. As an example, a “C/10” rate will basically return the battery to full charge in 10 hours. A C/8 rate is probably the highest current, which should be considered for charging under normal circumstances.

Battery Temperature Compensation

The Battery Float Voltage is set to the value recommended by the battery manufacturer in order to maintain correct battery charge at 25ºC. As temperature rises, electrochemical activity in a battery increases. Similarly, as temperature falls, electrochemical activity in a battery decreases. As temperature rises charging voltage should be reduced to prevent overcharge and increased as temperature falls to prevent undercharge. The power system uses Battery Temperature compensation to change output voltage to compensate for temperature changes. This temperature compensation function is programmed into the PSCU using the compensation parameters settings. Default settings can be changed to values recommended by the particular battery manufacturer.

MX28B400 +24 VDC User’s Manual

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Contents Page Table of Contents Remote Monitoring Revision History Revision Date DescriptionSafety First General PrecautionsIntroduction General Information2 MX28B-400 +24 Vdc System Wiring Diagram with Battery LVD How to Use This Manual Unpacking Equipment InstallationMechanical Installation Room / LocationAC Power Connections VentilationConnecting the Cables Battery ConnectionsPlanning the Battery installation Battery Temperature Probe Installation 2 Battery Temperature Probe InstallationDC System Grounding DC Power Output Over-Current Protection DC Circuit BreakersBreaker Part Number Adaptor Size Rating Plug-in Circuit Breaker Installation Load Cable Size ConsiderationsCircuit Breaker Connections 1 to 50 Amps Circuit Breaker Connections 60-100 AmpsFront Panel DB9 Connection Monitoring and Relay Output ConnectionsGMT Fuse Option Smart Cable DB9 ConnectionRJ45 Ethernet Connector Relay Output ConnectionsExternal Alarm Input Connections NO-NC-CRectifier Module Installation Initial Power-Up and CheckoutSystem Parameters Verification/Adjustment Battery Maximum Recharge Rate default = 12AFull System Power Up Rectifier Management OperationTechnical Description System Output Capacity System Status and Alarm ReportingSystem Management System Voltage ControlBattery Temperature Compensation Battery ManagementBattery Charging and Protection DC DistributionFront Panel User Interface Controls and IndicatorsBattery/Load Low Voltage Disconnect Status Alarms System Modules Batt PIN OEM Parameter Locations, Descriptions, and Default ValuesAddress Alarm ItemNo Alarms Switzer AvBatt Max Rechm+ Minor22.00 50 aComp TC Comp LkneeComp Method m+ 00mVHw Batt T Almm+ Fuse 1 AlmHw Batt C Almm+ Hw LVD AlmLamp Test DisableLVD Reset LVD OptionOut-Rly 1 Dly m+ Out-RlyRelay SecRect 1 Curr Rect CL AlmRect 1 CL 24.9Store Cfg Rect Stdby Almm+Rect 1 Stdby Sys CurrentSys Voltage Sys Temp26.7 Test Maj RlyStatus Alarms Control Unit Menu StructureV e l C o n d L e v e l I r d L e v e l U r t h L e v e l Sysout AP Alias MOD Modrec EM Modules Batt Rect Conv CIR SET-ALM Param MOD Modcir MOD Modlvd MT LVD SET-ALM Param Front Panel LED Indicators Alarm Outputs Output Relays External Alarm Inputs Input RelaysDescription Command and Monitoring ProtocolRemote Monitoring Physical Connections1MRF28H27BV Rectifiers SpecificationsAC Input 1MRF28H27BV50 RectifiersDC Output with either Rectifier RectifiersPower Shelf Control Unit PscuCompliance MechanicalEnvironmental APC Worldwide Customer Support Limited Product Warranty
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