Description

The HONEYWELL TC-PRS021 is a high-integrity, redundant-capable power supply module designed specifically for the Honeywell Safety Manager platform—a TÜV-certified, IEC 61508-compliant safety instrumented system (SIS) used in oil & gas, chemical, power, and pharmaceutical industries. Installed in Safety Logic Controller (SLC) racks, the TC-PRS021 delivers stable, filtered 24 VDC power to safety I/O modules, processors, and communication cards, ensuring uninterrupted operation even during partial power failures. With built-in diagnostics, hot-swap support, and full redundancy coordination, this module is foundational to achieving SIL2/SIL3 reliability in mission-critical applications.

Application Scenarios

At a North Sea offshore gas compression platform, an unexpected brownout caused intermittent resets in non-redundant power supplies across several safety subsystems—nearly triggering a false ESD (Emergency Shutdown). To eliminate single points of failure, engineers upgraded to dual HONEYWELL TC-PRS021 units in a redundant configuration within each Safety Manager SLC rack. During a subsequent grid fluctuation, one unit failed gracefully while the other instantly assumed 100% load—keeping all solenoid valves, pressure transmitters, and logic solvers online. “This isn’t just a power supply—it’s part of our safety architecture,” said the platform’s lead safety engineer. In environments where milliseconds matter and downtime risks lives, the HONEYWELL TC-PRS021 ensures the SIS never loses power—or trust.

Technical Principles and Innovative Values

Innovation Point 1: Seamless Redundancy with Active Load Balancing – When two TC-PRS021 units are installed, they dynamically share load (~50/50) and monitor each other’s health. If one fails, the other instantly ramps to 100% without voltage sag—ensuring zero disruption to safety logic execution.

Innovation Point 2: Integrated Diagnostics for Predictive Maintenance – Unlike generic PSUs, the TC-PRS021 reports real-time metrics (e.g., output voltage, temperature, fan status) to Honeywell Safety Builder, enabling early detection of capacitor aging or cooling issues before failure occurs.

Innovation Point 3: Safety-Certified by Design – Every component—from transformer insulation to fault detection circuitry—is validated under IEC 61508 for use in SIL3 loops. This eliminates the need for external safety relays or monitoring circuits.

Innovation Point 4: Universal Input for Global Deployment – Accepts both AC and DC plant power sources (e.g., 120 VAC in the US, 230 VAC in Europe, or 125 VDC battery banks), simplifying spares management across multinational sites.