General Information

• Brand: Foxboro (a brand under Emerson Automation Solutions)
• Model: A4H124-24TX
• Product Type: 24V DC Industrial Power Supply Module
• System Compatibility: Exclusively engineered for Foxboro I/A Series DCS – compatible with I/O racks, controllers, and field devices within the system.
• Core Function: Converts AC input power to regulated 24V DC output, delivering consistent power to connected DCS components. It includes protective features to safeguard against voltage fluctuations, overloads, and short circuits.

Technical Specifications

1. Power Input & Output

• Input Voltage: 100–240V AC (50/60 Hz, universal input) – adaptable to global industrial power grids.
• Input Current: 1.5A max (at 100V AC); 0.8A max (at 240V AC).
• Output Voltage: Regulated 24V DC ±2% (no-load to full load) – ensures stable power for sensitive electronics.
• Output Current: 4A continuous (maximum 5A peak for 10 seconds) – sufficient to power multiple I/O modules or field devices.
• Efficiency: ≥85% (at full load, 230V AC input) – minimizes power loss and heat generation.

2. Protection Features

• Overcurrent Protection: Automatically limits output current to 5.5A (self-resetting) – prevents damage to connected devices during overloads.
• Overvoltage Protection: Clamps output voltage at ≤28V DC – safeguards I/O modules and sensors from voltage spikes.
• Short-Circuit Protection: Latches off output during short circuits; requires manual reset (via front-panel switch) to restore – prevents sustained damage.
• Input Surge Protection: Withstands 2kV (line-to-line) transient surges – resistant to power grid fluctuations or lightning-induced spikes.

3. Physical & Environmental Specifications

• Dimensions: 120mm (W) × 100mm (H) × 60mm (D) [4.72” × 3.94” × 2.36”] – compact design for installation in Foxboro I/A Series control cabinets.
• Mounting: Rack-mounted (fits Foxboro standard 19-inch I/O racks) – integrates seamlessly with DCS components.
• Operating Temperature: -10°C to +55°C (14°F to 131°F) – suitable for indoor control rooms and enclosed cabinets.
• Storage Temperature: -40°C to +85°C (-40°F to 185°F).
• Humidity: 5%–95% RH (non-condensing) – resistant to moisture in humid industrial environments.
• Vibration Resistance: 10g (10–500Hz) per IEC 60068-2-6 – withstands vibration from nearby machinery.
• Protection Class: IP20 (front panel) – designed for enclosed cabinets (prevents dust ingress).

4. Safety & Compliance

• Certifications:
  • CE (EN 61010-1 for electrical safety, EN 61326-1 for EMC) – no interference with DCS signals.
  • UL 508 (industrial control equipment) – compliant for North American markets.
  • CSA C22.2 No. 14 – meets Canadian electrical safety standards.

Key Features

1. Universal Input: 100–240V AC input eliminates the need for region-specific power supplies, simplifying global deployments.
2. Stable Output: Regulated 24V DC with low ripple (<50mV peak-to-peak) ensures reliable operation of sensitive DCS components (e.g., analog I/O modules).
3. Comprehensive Protection: Overcurrent, overvoltage, and short-circuit protection prevent damage to expensive field devices and I/O modules.
4. Easy Monitoring: Front-panel LED indicators for power (green) and fault (red) – provides at-a-glance status for quick troubleshooting.
5. Seamless Integration: Custom-designed for Foxboro I/A Series DCS – aligns with rack mounting standards and wiring harnesses, reducing installation time.

Applications

• Oil & Gas: Powers pressure transmitters, flow meters, and valve positioners connected to Foxboro I/A Series DCS in wellhead or refinery control systems.
• Chemicals: Supplies power to reactor temperature sensors (RTDs) and chemical dosing pump controllers in batch process lines.
• Power Generation: Provides 24V DC to turbine vibration monitors and boiler feedwater control valves in fossil fuel or nuclear power plants.
• Water & Wastewater: Powers level sensors and pump starters in treatment plants, ensuring continuous operation of Foxboro-based monitoring systems.

Documentation & Support

• Technical Manual: Foxboro A4H124-24TX Power Supply Installation & Maintenance Guide (Document No. A4H124-24TX-UM) – available via Emerson’s Foxboro support portal, including wiring diagrams and troubleshooting steps.
• Spare Parts: Replacement fuses and reset switches are available through authorized Foxboro distributors.

Ordering Information

• Base Model: A4H124-24TX (24V DC, 4A output, universal AC input).
• Optional Accessories:
  • Mounting Brackets (A4H124-MT) – for non-standard cabinet installations.
  • Power Cord Kit (A4H124-CORD) – includes region-specific AC power cords.
• Lead Time: Typically 3–5 weeks for standard orders; 1–2 weeks for emergency spares.