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Huawei / Indoor Telecom Power Systems

DBU50B-N12A3 Equipment information & support

The DBU50B-N12A3 is a high-performance Huawei 48V 50A DC backup power unit engineered for telecom exchanges, cellular base stations, and critical ICT infrastructures. It integrates high-efficiency AC-DC rectification, intelligent battery charge/discharge regulation, and robust power distribution protection within a standard 19-inch embedded chassis, delivering uninterrupted 48V power to core loads.

Equipment information

Brand
Huawei
Equipment model
DBU50B-N12A3
Equipment type
Indoor Telecom Power Systems
Controller / software version
Confirm against the installed equipment
View full product specifications
Huawei DBU50B-N12A3 Embedded DC Backup Power Unit (-48V 50A 19-Inch Subrack) - Nameplate & Electrical Specifications

Information below comes from the current product catalogue. Confirm the controller, software version and configuration of the installed equipment separately.

Rated System Output Capacity
48V 50A DC
Input Voltage Range
85VAC ~ 300VAC (Single-Phase)
Battery Management
Intelligent Charge/Discharge & Temp Compensation
Cooling & Monitoring
Smart Fan Cooling & Remote Telemetry/Control
Form Factor
43.6 (1U) × 482 × 330 mm
Overall System Efficiency
Up to 96.2% (Gold Standard)

Alarms & troubleshooting

MAINS_FAIL / AC_POWER_LOSS (Utility Grid Failure / Total AC Ingress Loss)
Cabinet controller red ALARM LED solid with acoustic buzzer; system seamlessly transitions to battery discharge.
Grid utility failure, upstream transformer trip, automatic transfer switch (ATS) fault, or tripped main breaker.
1. Verify battery discharge current and remaining backup runtime on controller; 2. Start backup diesel generator (DG) and verify ATS transfer; 3. Measure incoming 3-phase line voltage and frequency stability; 4. Upon grid restoration, verify rectifiers soft-start and engage battery recharge.
LLVD_TRIP / LOAD_SHEDDING (Load Low Voltage Disconnect Tripped)
Controller LCD triggers LLVD alarm; LLVD contactor mechanically opens; secondary load branches de-energized.
Prolonged mains outage discharging batteries to protection threshold (typically 44.0VDC). System automatically sheds secondary loads to preserve core communications.
1. Confirm critical core branches (BLVD circuit) remain energized and protected; 2. Dispatch emergency mobile power generation cart to site; 3. Upon grid recovery, monitor DC bus voltage ramp above re-engagement threshold (48.0VDC); 4. Verify LLVD contactor re-closes and secondary equipment boots normally.
SPD_FAIL / SURGE_ARRESTOR (Surge Protective Device Degradation / Tripped)
Controller registers SPD alarm; SPD module inspection window turns from Green to Red; alarm dry contact closes.
Site subjected to lightning surge strike or sustained overvoltage, causing MOV thermal breakdown and disconnect.
1. Inspect SPD indicator flags (red flag confirms blown cartridge); 2. Check SPD dedicated backup fuse or circuit breaker; 3. Open SPD isolation switch, extract damaged plug-in cartridge; 4. Replace with genuine replacement cartridge matching rating (20kA/40kA); 5. Close circuit, verify green status flag and alarm self-clearing.

Access Complete Maintenance & Full Alarm Troubleshooting Manual

This page lists high-frequency critical alarm codes commonly encountered in field maintenance. Comprehensive manufacturer troubleshooting matrices, board-level repair guides, detailed electrical schematics, and firmware commissioning manuals are delivered alongside equipment upon formal project procurement, accompanied by dedicated FAE technical support.

Contact Account Manager for Full Manual

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