Model No. 3BHB006449R0002, internal part designation MPS 10/5-230/24/48, is a DIN rail-mounted dual-channel switching power supply exclusively developed by ABB Original Equipment Manufacturer for excitation control systems and the 800xA DCS distributed control platform. Its matched OEM auxiliary power supply accessory is the MURR Elektronik Model 857781 filter and voltage stabilizer unit made in Germany. The two units are used as a complete set, delivering stable isolated DC power supply for power plant excitation cabinets, metallurgical rectifier control cabinets and heavy-duty drive control systems.
Manufactured at ABB’s original factory in Switzerland, this module features wide-range AC input and dual simultaneous outputs: 24V control power and 48V auxiliary excitation power, with a total output power of 250W. Adopting fanless natural convection cooling, it enables long-term continuous operation inside industrial control cabinets with heavy dust and severe electromagnetic interference (EMI). Serving as the front-end EMC filter unit, the MURR 857781 suppresses grid harmonics and voltage surges, and eliminates power output drift caused by grid voltage fluctuations.
The complete power supply solution holds CE and UL industrial safety certifications, and serves as the standard OEM power supply kit for ABB excitation systems. It is widely applied for spare part replacement on legacy excitation equipment and full-set configuration of new control cabinets.
Core Advantages
Factory-matched Complete Set with Zero Compatibility Failures
The ABB power supply unit paired with the MURR 857781 filter constitutes a standard factory matching assembly. Its internal circuit timing sequence and impedance parameters are calibrated by the original manufacturer. It avoids common defects of generic third-party filter modules such as output voltage drop and excessive inrush starting current. Direct replacement of old complete assemblies requires no wiring parameter adjustment.
Dual Independent Isolated Outputs for Hierarchical Power Management
The 24V/5A output supplies controllers, IO modules and relay circuits, while the 48V/2A output exclusively feeds excitation trigger boards and auxiliary power circuits. The two outputs feature electrical isolation. A short circuit on one load will not cut off power to the other control circuit, ensuring uninterrupted basic unit control.
Maintenance-free Fanless Cooling for Harsh Cabinet Environments
The unit adopts an all-aluminum heat sink housing cooled by natural convection, with no wearable fan components. It eliminates shutdown failures caused by dust-clogged fans common at power plant and metallurgy sites, drastically cutting annual maintenance frequency.
Ultra-wide Grid Compatibility & Superior Anti-interference Filtering
It supports full-range single-phase AC input of 85~264V, suitable for captive power plants and smelting plants with unstable grid voltage. Equipped with two-stage EMI filtering via the MURR 857781, it suppresses high-frequency interference generated by inverters and rectifiers, resolving issues including fluctuating DCS signals and false excitation triggering.
Multi-layer Hardware Protection to Minimize Equipment Wear
Built-in five protection functions: overvoltage, overcurrent, short-circuit, reverse polarity and over-temperature shutdown. In case of load faults, the module latches output automatically to prevent reverse breakdown of downstream CPUs and excitation boards, lowering high costs for board repair and replacement.
Standard DIN Rail Mounting for Easy Cabinet Retrofit
Designed with standard 35mm DIN rail clips. It serves as a drop-in replacement for older single-output ABB power supplies of the same dimension. No modifications to cabinet cutouts or terminal layouts are needed, cutting spare part retrofit construction time by half.
Detailed Specifications
Electrical Parameters
AC Input: 85~264V AC, 50/60Hz, compatible with single-phase 110V and 220V power supply in plant areasDual DC Outputs: 24VDC/5A and 48VDC/2A with independent voltage regulation for each channel; ripple coefficient ＜120mVConversion Efficiency: ≥90% under full load, low power consumption reduces heat accumulation inside cabinetsTotal Output Power: 250W; short-term peak load capacity increased by 15%Insulation Isolation: 3000V high-voltage isolation between input and both output channels, preventing electric leakage and resisting ground loop interference
Environmental & Structural Specifications
Operating Temperature: -10℃ ~ +60℃, stable operation without additional cooling fans in control cabinets; Storage Temperature: -40℃ ~ +85℃Protection Class: IP20, designed for internal cabinet installation to avoid accidental finger contact with live terminalsMounting Standard: Standard 35mm DIN rail; Overall dimensions: 215×115×50mm, net weight 2.7kgCooling Method: Integrated aluminum extrusion natural cooling, no rotating componentsCertifications: CE, UL, GL marine certification, complying with access standards for power and heavy industry sectors
Protection Functions
Short-circuit protection, overcurrent current-limiting protection, output overvoltage latching protection, input reverse polarity burnout prevention, automatic power derating / shutdown upon overtemperature, surge impact suppression.Passive fault alarm contacts are built-in for connection to DCS to upload fault signals.
Matching Filter Specifications of MURR 857781
Two-stage LC filter circuit suppresses high-frequency electromagnetic interference ranging from 10kHz to 30MHz, reduces grid harmonic distortion rate, mitigates interference to control power generated by rectifier cabinets and high-power inverters, and eliminates false fault alarms of excitation systems as well as analog signal drift of DCS.
Application Industries
Thermal / Hydropower / PV Power Plants
Power supply for excitation control cabinets of steam and hydroelectric generating units as well as the 800xA DCS system. It provides complete power for excitation trigger circuits, synchronizing devices and background IO modules, serving as the standard OEM power solution for power plants.
Metallurgy & Non-ferrous Metal Industry
High-power rectifier control cabinets for aluminum electrolysis and copper smelting, as well as excitation control systems of main rolling mill drives. Factory grids suffer severe harmonic interference, and the matched MURR filter stabilizes power supply for control circuits.
Heavy Equipment & Mining
Excitation cabinets for synchronous motors of large hoists and ball mills, as well as underground central control cabinets. Adaptable to on-site conditions with severe voltage fluctuation and heavy dust.
Chemical, Petroleum & Refining Industry
Excitation speed control systems of large compressor units and catalytic installations. It delivers isolated power inside explosion-proof control cabinets to guarantee uninterrupted control output.
Shipbuilding & Marine Engineering
Marine excitation control systems for large generator sets, complying with marine safety standards for wide temperature range and anti-vibration performance.
FAQ
Q: Can Model 3BHB006449R0002 be purchased and used separately without the MURR 857781 filter?A: Separate use is not recommended. This power supply is designed for high-power rectifying excitation equipment, where on-site grids carry heavy harmonics and surge impulses. Removing the 857781 filter will lead to latent long-term faults including output voltage drift, DCS signal jitter and false excitation alarms. The two units are supplied as a standard factory matched set. Purchasing them as a complete kit is more reliable for new projects and spare part replacements.
Q: Are there any discontinued alternative models for this power supply? Can it be directly used for retrofitting old excitation cabinets?A: 3BHB006449R0002 remains in mass production with no official discontinuation notice. Older MPS power supplies from the same series share identical mounting dimensions and terminal definitions. The unit clips directly onto the DIN rail without modifying cabinet cutouts or wiring circuits; only load power matching needs to be verified.
Q: How many sets of excitation trigger boards and DCS IO modules can one complete power unit drive simultaneously?A: The rated current of the 24V channel is 5A, capable of powering 8 to 12 S800 IO modules plus one controller. The 48V channel rated at 2A is exclusively for excitation trigger boards, supporting a maximum of 3 groups of pulse boards. Neither channel can exceed its rated load, otherwise overcurrent protection will activate and shut down the unit.
Q: After power-on, the 24V output works normally but no voltage is available on the 48V channel. What causes this fault?A: First check for short circuits or breakdown of load boards on the 48V output circuit. Second, inspect whether the internal fuse of the 48V branch is blown. Long-term high temperature and surge impulses are the main causes of blown fuses. The short-circuit point on downstream loads must be located before replacing the fuse.
Q: The DCS repeatedly reports signal faults under grid voltage fluctuations in the control cabinet, and the issue persists after replacing the power supply.A: This is most likely caused by aging and failure of the front-end MURR 857781 filter. Degraded filter capacitors fail to suppress harmonics. Only the filter needs to be replaced to restore normal operation, instead of the whole power set. Technicians shall prioritize testing the input and output waveforms of the filter during maintenance.
Q: The module housing becomes extremely hot after a period of operation, exceeding 60°C. How to resolve this issue?A: 1. Clear dust accumulated in the aluminum heat sink grooves;2. Check if either output channel is overloaded;3. Confirm whether the gap between the power supply and filter is less than 3cm or cabinet ventilation is poor.Never cover the heat-dissipating housing. Long-term high-temperature operation accelerates aging of internal electrolytic capacitors.
Q: The fault alarm contact of the power supply stays closed permanently, yet normal operation resumes after a full power cycle. What is the root cause?A: This issue is usually triggered by transient grid surges that latch the overvoltage protection, accompanied by degraded filtering performance of the matched MURR 857781 filter. Regular filter replacement and installation of surge protection devices inside cabinets can reduce such occasional faults and prevent unplanned unit shutdowns.
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