Product Core Brief
- Model: P0973LQ
- Brand: FOXBORO (Schneider Electric EcoStruxure Foxboro)
- Series: Foxboro Evo DCS Control Network Infrastructure
- Core Function: Convert universal AC mains to regulated 24 VDC power for Evo network switches and FDSI communication hardware
- Product Type: 1U rack-mount hot-swappable AC-DC industrial power supply
- Key Specs: 480 W total output | Dual redundant AC inputs | 20 A max 24 VDC load | ⚠️ EOL — limited stock remaining, Condition: New Surplus Original
Product Introduction
FOXBORO is a 1U rack power supply built exclusively to energize Foxboro Evo control network fiber and Ethernet switching hardware inside process control cabinets. It accepts two separate AC feeds to support N+1 redundant power architectures for critical DCS networks.This unit outperforms smaller 300 W rack supplies by delivering 60% higher continuous DC output, with a measured MTBF of 290,000 hours at 40 °C cabinet ambient. Internal foldback current limiting isolates shorted downstream network hardware without full supply shutdown.
Key Technical Specifications
| Parameter | Value |
|---|---|
| AC Input Range | 100–240 VAC, 50/60 Hz auto-sensing, dual redundant input terminals |
| Rated DC Output | 24 VDC, 20 A continuous, 480 W maximum combined power |
| AC Input Current Draw | 5.3 A max at 110 VAC, 4.7 A max at 220 VAC full load |
| Power Conversion Efficiency | 87% nominal efficiency at 70–100% rated load |
| Mount Form Factor | Standard 19 in equipment rack, 1U height (4.4 cm) |
| Cooling Mechanism | Internal axial cooling fan with replaceable inlet filter grille |
| Protection Circuits | Overvoltage, overcurrent foldback, short-circuit auto-recovery, thermal shutdown |
| Diagnostic Indicators | Front-panel LED status for AC input, 24 V output, thermal fault |
| Operating Temperature Range | 0 °C to +50 °C operational; -40 °C to +70 °C storage |
| Humidity Rating | 5–95 % relative humidity, non-condensing environment |
| Environmental Coating | ISA S71.04 G3 conformal PCB coating for corrosive plant atmospheres |
| Hazardous Certifications | FM Class I Div.2, ATEX Ex ec IIC Gc (cabinet-only installation) |
| Compatible Load Hardware | Evo control network fiber switches, FBM232 / FBM233 FDSI gateway modules |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-reference serial numbers to OEM production batch logs; inspect fan filter grille, AC screw terminals, and front LED panel for dents or cracked plastic housing. Reject units with damaged fan impellers.
- Live Functional Test: Mount the unit on a standard 19 in test rack, connect dual AC input feeds, attach a 480 W resistive DC load bank, run a 26-hour continuous full-load cycle. Log internal heat sink temperature and verify stable 24 VDC output regulation.
- Electrical Parameter Test: Use a 500 V Megger to test input-to-output insulation resistance (minimum pass threshold 10 MΩ); verify chassis ground continuity to rack mounting lugs.
- Firmware Verification: Read embedded fault monitoring firmware revision via front-panel test points; photograph factory fan speed threshold settings for post-delivery reference.
- Final QC & Packaging: Purge internal PCB and fan surfaces with dry nitrogen to remove industrial dust buildup; seal the supply in anti-static vacuum bag, apply QC Passed sticker stamped with full test completion date.
Replacement Pitfall Guide
❗ Firmware Mismatch: Older Evo network switch firmware cannot parse fault telemetry from newer firmware revisions on the unit. Confirm switch software rev before ordering spare power hardware — site DCS upgrade schedules often lag spare component stock.❗ DIP Switch / Jumper Misconfiguration: Factory default jumpers enable single AC input mode only. The second terminal header on the rear panel activates dual redundant AC failover; misalignment disables automatic switchover during mains loss.❗ Terminal / Cable Incompatibility: 14 AWG or smaller AC input wiring creates excessive voltage drop under full 20 A DC load. Use minimum 12 AWG stranded copper for all redundant AC feed runs longer than 10 m.❗ Power Supply Mismatch: Calculate total downstream network load with 20% headroom. Three FBM232 gateways plus one fiber switch draw 12 A combined; pairing undersized 300 W supplies triggers thermal fault LED trips during peak network traffic.❗ ESD Damage: Always deploy an anti-static mat in low-humidity winter cabinet environments. Static discharge to the exposed DC output PCB traces damages internal foldback limiting circuits with no visible exterior damage.Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
Compatibility Matrix
- Evo Fiber Switch Chassis → : Direct drop-in replacement — no AC/DC wiring edits required
- FBM232 P0926GW Gateway → : Direct load power source — matches 24 VDC current draw profile
- FBM233 Dual Ethernet Gateway → : Direct load power source — combine multiple gateways with load margin calculation
- DeltaV Rack Power Shelf → : Incompatible — different DC output voltage and rack form factor
- Ovation Q-Line Power Module → : Incompatible — proprietary 24 V bus pinout and mounting dimensions
- FBM207 I/O Base → : Needs Adaptation — requires separate DC marshalling terminal block for field I/O loads
Benchmarks
- DC output regulation tolerance: ±0.5 V (0–100% variable resistive load)
- Redundant AC failover latency: < 15 ms seamless transfer between primary/secondary mains feeds
- Thermal shutdown threshold: 68 °C internal heat sink temperature (auto-restart after cool-down)
