Application Scenarios

On a 110 kV urban-suburban ring in Southern Europe, the utility’s protection engineer was chasing a maddening pattern: during monsoon thunderstorms, two SR-series line-protection panels on the 110 kV bus would log “24 V Aux Undervoltage” and reboot right when the feeder needed to see the fault. The panels drew station DC from a 110 V DC battery float, but the old internal PSU — a 12-year-old unit from the original panel build — couldn’t hold regulation when the 110 V DC bus dipped to ~95 V during the battery inverter’s equalization cycle. Swapping in the 1MRK002238-DA​ (SR91C830) fixed two things at once: first, its 110–250 V DC input window comfortably covered the battery’s low-end excursion; second, the self-recovering overload meant a sticky binary-output relay coil no longer took the whole 24 V rail down — the PSU folded back, lit its fault indicator, and resumed once the coil freed. Post-retrofit, the “Aux Undervoltage” events on those two panels dropped from 4–5 per monsoon season to zero over 18 months. For any utility still running SR/SPACOM-era panels alongside newer Relion 615/650 bays, keeping a couple of 1MRK002238-DA​ modules on the shelf is cheaper than explaining a nuisance reboot to the regulator.

Parameter

Main Parameters	Value/Description
Product Model	1MRK002238-DA​ (Type: SR91C830)
Manufacturer	ABB
Product Category	Protection Panel Power Supply Module (1MRK family)
Input Voltage Range	85–264 V AC (47–63 Hz) / 110–250 V DC
Rated Output	24 V DC
Output Current	4 A (continuous)
Rated Power	~96 W (24 V × 4 A)
Conversion Efficiency	≥ 95 %
Protection Functions	Short-circuit, overcurrent, overvoltage, overtemperature (self-recovering)
Operating Temperature	-25 °C to +70 °C
Protection Class	IP20 (panel-internal mounting)
Mounting Method	Panel/internal rail or screw-fixed (PCB assembly format)
Dimensions (W×H×D)	~90 × 51 × 50 mm (compact version) / ~134 × 56 × 123 mm (alternate version per batch)
Weight	~0.2 kg
Certifications	CE, UL, cUL, GL (typical)

 

Technical Principles and Innovative Values

• Innovation Point 1: Dual AC/DC Wide-Range Input Tuned for Station Supplies.​ The 1MRK002238-DA​ isn’t a generic 24 V brick — its 85–264 V AC / 110–250 V DC input span is deliberately aligned with substation realities: 110 V DC battery float, 220 V DC switchgear supply, and 230 V AC station service all land on the same primary. That means one spare part travels between DC-bitten utility sites and AC-only industrial plants without a re-spec.
• Innovation Point 2: Self-Recovering Protection Without Fuse Swap.​ A sticky binary-output relay or a miswired DI loop can drag the 24 V rail down hard. The 1MRK002238-DA​ folds back current on short/overload, flags the fault locally, and auto-resumes once the condition clears — no fuse pull, no nighttime callout, just clear the wiring fault and watch the relay panel come back.
• Innovation Point 3: ≥95 % Efficiency in a PCB-Format Package.​ At 96 W, the 1MRK002238-DA​ holds efficiency above 95 % across most of the load curve. In a sealed relay panel during a +45 °C Mediterranean summer, that extra few percent versus an 88 % unit keeps the internal convection budget from strangling the protection relay CPU — and extends the life of everything sharing that panel.

 

Application Cases and Industry Value

A municipal utility in Northern Europe ran a mixed-age 132/33 kV substation where three SR-series line-protection panels (commissioned ~2010) shared a cramped relay cubicle with newer REF615 bays. During a scheduled 110 V DC battery replacement, the old PSUs in two SR panels couldn’t track the slow DC ramp-up and threw “Aux Loss” three times in one morning, forcing the protection engineer to camp on-site. The retrofit swapped all three SR-panel PSUs to the 1MRK002238-DA​ (SR91C830). Besides solving the ramp-track issue, the 1MRK002238-DA‘s 110–250 V DC window also future-proofed the panels for a planned move to 220 V DC float (common in newer utility specs). Post-retrofit walkdowns noted one detail the engineer hadn’t planned: the 1MRK002238-DA​ ran cool enough that the cubicle’s top-mounted fan, previously audible during summer peaks, rarely ramped up — a small quality-of-life win for the control-building HVAC budget.