Description:The 1MRK002238-DA, also identified by the type code SR91C830, is an ABB industrial-grade 24 V DC power supply module designed to deliver stable, regulated DC power to ABB protection relay racks (Relion® series auxiliary racks), Bailey INFI 90 / Net 90 DCS panel components, S800 I/O system power feeds, and other 24 V DC control loads. It accepts a universal AC input (85–264 V AC) and provides a clean, short-circuit-protected 24 V DC output with high conversion efficiency, making it a foundational component for reliable control system operation.h2 Application Scenarios:In a large combined-cycle power plant, the control room houses multiple Bailey INFI 90 I/O racks and a standalone annunciator panel fed from a single 24 V DC power supply that had aged beyond its design life—output ripple was increasing and the DC bus occasionally dipped below the undervoltage lockout threshold during summer peak loading. The E&I team proactively replaced the failing unit with the 1MRK002238-DA SR91C830 power supply module, paralleled with a second unit for N+1 redundancy. The 1MRK002238-DA delivered a rock-steady 24.0 V DC under full load, with the front-panel green LED confirming healthy operation at a glance. More importantly, the built-in overload and short-circuit protection gave the team confidence that a downstream field-wiring fault on one I/O card wouldn’t cascade to a total rack power loss. Since the swap, the plant has gone through two summer peaks with zero DC-power-related trips. The lead technician remarked that the 1MRK002238-DA “restored margin we didn’t know we’d lost—now the DC bus is boring again, which is exactly what we want.”h2
Parameter:
| Main Parameters | Value/Description |
|---|---|
| Product Model | 1MRK002238-DA (Type SR91C830) |
| Manufacturer | ABB |
| Product Category | Switch-Mode Power Supply Module (24 V DC Output) |
| Input Voltage | 85 – 264 V AC (universal), 47 – 63 Hz; also accepts 120 – 370 V DC on some variants |
| Output Voltage | 24 V DC ± 1 % (adjustable ± 5 % via potentiometer on select versions) |
| Rated Output Current | 5 A (120 W typical) / some references list 2 A (48 W) for compact variant — verify your load requirement |
| Output Power | 48 W – 120 W depending on variant (SR91C830 typically 48–60 W class for relay/aux rack use) |
| Ripple & Noise | < 150 mV pp (typical, 20 MHz BW) |
| Efficiency | ≥ 89 – 92 % (typical at full load) |
| Protection Features | Short-circuit proof, overload (hiccup mode), over-temperature, inrush current limiting |
| Status Indication | Green LED = Output OK; Off or Red = Fault / No Output |
| Parallel / Series Capability | Supports parallel operation for N+1 redundancy or increased current (parallel mode on redundant-ready variants) |
| Operating Temperature | -10 °C to +60 °C (derating above 50 °C on some models) |
| Mounting Method | 35 mm DIN rail (TS35) or panel mount with screws |
| Protection Class | IP20 (touch-safe terminal cover recommended) |
| Dimensions (approx.) | 55 × 90 × 110 mm (W × H × D) for standard 120 W class; smaller for 48 W variant |
| Certifications | CE, UL 508 / UL 60950, cULus, RoHS |
h2 Technical Principles and Innovative Values:
- Innovation Point 1 — Universal AC Input with Active Power Factor Correction (select models). The 1MRK002238-DA is designed to operate globally without voltage selector switches, accepting 85–264 V AC single-phase. This eliminates the common mistake of mis-setting a 115/230 V selector when relocating or replacing a PSU. High-frequency switch-mode topology with PFC (where fitted) minimizes input current draw and reduces heating in upstream UPS/transformer windings.
- Innovation Point 2 — True Short-Circuit Proof & Hiccup-Mode Auto-Recovery. Unlike fused linear supplies that require manual reset after a fault, the 1MRK002238-DA enters a low-power “hiccup” state on output short or severe overload, periodically testing for fault clearance. Once the short is removed (e.g., a bad I/O card is pulled), the unit automatically resumes regulation—no breaker to flip, no technician dispatched for a simple wiring fault. This self-recovering behavior is critical in remote or unmanned substations.
- Innovation Point 3 — Redundancy-Ready Design with Diode-OR Capability. The module’s output stage is stable when paralleled with an identical unit through external OR-ing diodes (or ABB redundancy module), enabling N+1 redundant architectures for critical DCS/IED power feeds. The 1MRK002238-DA‘s tight output regulation and low drift ensure balanced load sharing, extending the life of both units versus cycling a single oversized supply near its thermal limit.
