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Vertiv / UPS Power & Backup Systems

Liebert PM50-B Equipment information & support

The Vertiv Liebert PM50-B is a 50kVA modular precision UPS distribution power cabinet engineered for small-to-medium data centers and mission-critical industrial facilities, featuring online double conversion.

Equipment information

Brand
Vertiv
Equipment model
Liebert PM50-B
Equipment type
UPS Power & Backup Systems
Controller / software version
Confirm against the installed equipment
View full product specifications
Vertiv Liebert PM50-B Modular Precision UPS Distribution Cabinet (50kVA Subrack) - Official Front View

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

Rated Distribution Capacity
50kVA / 45kW (Scalable Architecture)
AC Input Voltage
380V / 400V / 415V AC (3-Phase 4-Wire)
Power Topology Architecture
Online Double-Conversion
Online Operating Efficiency
96%
Maintenance Bypass Switch
Built-in Static Bypass & Manual Maintenance
Nominal DC Output Voltage
-48VDC (-42V ~ -58V)

Alarms & troubleshooting

MAINS_FAIL / AC_POWER_LOSS
Power distribution Amber LED solid, controller buzzer active
Mains utility grid failure, upstream transformer trip, or main AC breaker open
1. Verify battery discharge current and remaining backup runtime on monitor;\n2. Start standby generator (DG) and confirm transfer switch closure;\n3. Measure incoming 3-phase AC voltage and frequency stability;\n4. After grid recovery, verify rectifiers soft-start and initiate boost charging.
LLVD_TRIP / LOAD_SHEDDING
Controller screen displays LLVD alarm, DC load contactor opened
Prolonged blackout caused battery voltage to drop below threshold (44.0VDC default), shedding non-critical loads
1. Confirm priority telecommunication loads on BLVD branch remain powered;\n2. Deploy mobile emergency power generators to replenish battery plant;\n3. Upon grid restoration, observe DC bus rising past reset threshold (48.0VDC);\n4. Verify all load shedding contactors re-engage and resume service.
SPD_FAIL / SURGE_ARRESTOR
Surge arrestor inspection window turns Red from Green, alarm relay closed
Lightning induced transient surge or utility overvoltage caused MOV thermal breakdown and disconnection
1. Inspect visual disconnect indicator window on AC surge protector module;\n2. Verify upstream SPD backup fuse or miniature circuit breaker status;\n3. Open SPD circuit breaker and pull out damaged plug-in cartridge;\n4. Insert genuine replacement cartridge (20kA/40kA rating) and reset breaker.

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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