Foxboro FBM230 Redundant Power Supply Module

Technical Specifications:

• Input Voltage: 120 VAC or 240 VAC (auto-sensing), 50/60 Hz
• Input Current: 4A maximum at 120 VAC; 2A maximum at 240 VAC
• Output Voltage Rails:
  • +5V DC — 20A maximum
  • +24V DC — 10A maximum
  • ±15V DC — 2A maximum
  • +5V Standby — 1A (for redundancy keep-alive)
• Redundancy Type: Dual-input, dual-output hot-standby redundant
• Efficiency: Greater than 80% at full load
• MTBF (Mean Time Between Failures): Greater than 200,000 hours
• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Protection: Overcurrent, overvoltage, short-circuit, and thermal shutdown protection

Functional Features:

• Provides redundant power paths — if one input fails, the other seamlessly takes over with zero interruption (transfer time less than 1 millisecond)
• Delivers five independent DC voltage rails to power all module types in the chassis
• Includes built-in diagnostics for input voltage, output voltage, and current monitoring
• Front panel LED indicators for POWER OK, REDUNDANCY OK, and FAULT status
• Supports N+1 redundancy configuration — one FBM230 can support multiple chassis in daisy-chain power distribution

Performance Parameters:

• Power Capacity: Total output power of 250 Watts
• Ripple and Noise: Less than 50 mV peak-to-peak on all DC outputs
• Voltage Regulation: ±1% on all output rails under full load variation
• Transfer Time: Less than 1 ms during input source switchover
• Hold-Up Time: Greater than 20 ms at full load (sufficient for backup power bridging)

Material Composition:

• Enclosure: Steel chassis with zinc-nickel plating for corrosion resistance
• PCB: FR-4 fiberglass epoxy, conformal coated with silicone-based coating
• Connectors: Gold-plated pins for backplane interface, tin-plated for power input terminals
• Fan: Brushless DC cooling fan with ball bearing, rated for 50,000 hours operation

Structural Characteristics:

• Form Factor: Standard Eurocard module (160 mm × 233 mm)
• Mounting: Horizontal rack mount
• Connectors: Dual backplane connectors (redundant), screw-terminal AC input connectors
• Cooling: Forced air cooling via chassis fan tray
• Weight: Approximately 1.2 kg (2.65 lbs)

Working Principle:
AC mains power enters the FBM230 through two independent input terminals (primary and secondary). Each input feeds a separate rectifier and DC-DC converter stage. The outputs are OR-ed together via diode isolation so that either input can independently supply all DC rails. The redundancy controller continuously monitors both input sources and output voltages. Upon detection of a primary input failure, the system switches to the secondary input within less than 1 ms, with no interruption to the DC outputs powering the chassis modules.

Advantages & Highlights:

• True hot-standby redundancy — no interruption during power source failover
• Five independent regulated outputs — eliminates need for separate power supplies
• Comprehensive built-in diagnostics — reduces troubleshooting time
• Universal AC input (120/240 VAC) — simplifies global deployment
• High efficiency design — reduces heat generation and cooling requirements

Applicable Industries:

• Oil and Gas Refining
• Chemical Processing
• Power Generation
• Pharmaceutical Manufacturing
• Pulp and Paper
• Water Treatment

Installation Requirements:

• Install in any available slot in the Foxboro I/A Series chassis (slot position does not affect function)
• Connect both AC input sources to separate circuit breakers for true redundancy
• Ensure chassis ground connection is established before powering on
• Verify chassis fan tray is operational — FBM230 requires minimum airflow of 100 CFM

Usage Precautions:

• Do not connect both AC inputs to the same circuit breaker — defeats redundancy purpose
• Verify input voltage selection matches local mains before energizing (auto-sensing handles 120/240 VAC but verify frequency is 50/60 Hz)
• Do not block airflow — overheating will trigger thermal shutdown
• Replace fuse only with identical rating — internal fuses are 5A slow-blow type