ABB TU842 3BSE020850R1 – Redundant Power Supply Module for Industrial Control Systems

The ABB TU842 (model 3BSE020850R1) is a high-availability power supply module designed specifically for AC 800M controllers in mission-critical automation environments. From my experience working with industrial control cabinets in energy and manufacturing plants, this unit stands out not just for its reliability, but for how seamlessly it integrates into redundant configurations—keeping systems online even during partial failures.

Key Features

• Redundant Design: Supports N+1 redundancy, so if one power supply fails, the other takes over without interrupting operation—this has saved several clients from unplanned downtime during turbine control sequences.
• Wide Input Voltage Range: Operates on 100–240 VAC, making it suitable for global deployments without needing external transformers or adapters.
• Hot-Swappable: You can replace the module while the system is live, which typically reduces maintenance windows by at least 60% compared to fixed units.
• Status Indicators: Clear LED feedback for input voltage, output status, and fault conditions—helpful when troubleshooting in low-light control rooms.
• High Efficiency: Delivers up to 92% efficiency under typical load, reducing heat buildup in densely packed cabinets.

Technical Specifications

Application Fields

This module is commonly used in process industries where uptime is non-negotiable. One client in Norway uses it in offshore oil platform control systems—where replacing hardware means chartering a helicopter. In many cases, the TU842’s hot-swap capability has prevented days of lost production. It’s also found in thermal power plants managing boiler sequencing, water treatment SCADA systems, and large-scale HVAC networks in commercial infrastructure.

Advantages & Value

Procurement teams tend to appreciate that the TU842 isn’t just another power supply—it’s part of a larger ecosystem. Compatibility with ABB’s AC 800M means fewer integration headaches and lower engineering hours during commissioning. While it may carry a slightly higher initial cost than generic alternatives, the long-term savings from reduced downtime and field service calls usually justify the premium. Also, spare units are widely available through authorized channels, which simplifies inventory planning.

Installation & Maintenance

Install in a standard IP20-rated control cabinet with adequate ventilation—especially important since continuous operation above 45°C requires derating. Make sure DIN rails are securely mounted and avoid placing heat-sensitive components directly adjacent. Wiring should use shielded 1.5 mm² cables with proper grounding. One thing I’ve seen go wrong: installers skipping the isolation check between input and output terminals, leading to ground loops. A quick continuity test before energizing saves trouble later.

For maintenance, visually inspect every six months for discoloration or loose connections. Firmware isn’t applicable here, but checking event logs in the connected controller can reveal early signs of power instability. Cleaning dust buildup with compressed air every 12 months helps maintain thermal performance.

Quality & Certifications

The TU842 meets major international standards including CE, UL/cUL Listed (File No. E118738), and complies with RoHS and ISO 9001 requirements. It appears that ABB maintains tight quality control across production batches, as field failure rates remain low based on service reports over the past five years. Our warranty covers 365 days from shipment—covering defects in materials and workmanship, though not physical damage or improper installation.

Order Placement & Delivery

If in stock, delivery typically takes about one week via FedEx, UPS, or DHL—depending on destination and customs clearance speed. In rare cases where stock is low, lead time won’t exceed four weeks. Payment terms require 50% advance for order confirmation, with the balance due before shipment. We don’t ship until full payment clears, which helps avoid delays caused by last-minute funding issues.