GE DS3800NPCR1A1A

Key Technical Parameters

Advantages and Distinctive Features

• Relay-Primary Hybrid + Tachometer Feedback: 8 high-current mechanical relays (5A) + 4 solid-state DC outputs (3A) + 2 tachometer inputs on a single board.

• Dual Temperature Sensor Support (T/C + RTD): 8 thermocouple + 8 RTD inputs (16 total channels).

• Higher Relay Current (5A): Supports larger AC/DC fans compared to 3A relay boards.

• Higher Solid-State Current (3A): Supports larger DC auxiliary loads compared to 2A boards.

• RTD Fault Detection: Continuous monitoring for open-circuit, short-circuit, or lead-wire degradation.

• Baseline Revision A: The original version of this board—ideal for direct replacement in legacy systems.

• Complete Galvanic Isolation: 2500V isolation on relay outputs.

• Fan Speed Verification: Tachometer inputs allow CPU to confirm fan operation.

Typical Application Fields

• Safety-Critical Mixed Fan Systems: Where high-power fan control, redundant temperature sensing, and fan failure detection are mandatory.

• Mixed Fan Cabinets: Where high-power AC/DC fans and DC auxiliary devices coexist with both T/C and RTD sensors.

• Nuclear Auxiliary Turbines: High reliability with redundant temperature sensing.

• Legacy System Replacements: Direct drop-in replacement for original DS3800NPCR boards.

• Climate-Controlled Indoor Installations: 0°C to +60°C range.

Comparison with Related Models

Selection Recommendations

• Choose the DS3800NPCR1A1A if:

  • You need 8 high-current mechanical relay outputs (5A) for main fans.

  • You also need 4 solid-state outputs (3A) for DC auxiliary devices.

  • You require both thermocouple and RTD inputs (16 total channels).

  • You require RTD fault detection for sensor integrity monitoring.

  • You require tachometer feedback for fan speed verification.

  • You have a climate-controlled environment (0°C to +60°C).

  • You need a direct replacement for an existing DS3800NPCR board.

• Choose the DS3800NPCM1B1B if: You need 8 SS outputs and 4 relay outputs with improved accuracy and extended temperature range (-20°C to +65°C).

• Choose the DS3800NMEC1E1E if: You need 8 relay outputs and 4 SS outputs without tachometer feedback but with predictive thermal modeling and extreme temperature range (-40°C to +85°C).

Critical Precautions

• ESD Protection: Always wear a grounded wrist strap.

• High-Voltage/Current Hazard (Relay): Relay outputs switch 115VAC/5A—lethal. Use proper insulation.

• Relay Inductive Derating: For inductive fan motors, derate from 5A to 3.5A or use RC snubbers.

• DC Polarity (SS): Solid-state outputs are DC-only and polarity-sensitive—reverse polarity destroys the MOSFET.

• SS Voltage Limit: Do not exceed 48VDC—AC voltages cause catastrophic failure.

• RTD Wiring: Use 3-wire Pt100 RTDs. All three wires must be connected. Open/short circuits trigger RTD Fault LED.

• RTD Lead Resistance: Use wire with resistance ≤10Ω per lead for accurate measurements.

• Tachometer Wiring: Use shielded twisted-pair cable. Connect shield to designated terminal—not at the fan end.

• No Hot-Swap: Always depower the rack before insertion/removal.

• Slot Assignment: Install in slots 8–10 (auxiliary I/O).

• CPU Dependency: If backplane communication is lost, the board defaults to 100% fan speed—tachometer monitoring and RTD fault detection disabled in fallback mode.

• Firmware Compatibility: The DS3800NPCR1A1A is compatible with Mark V CPU firmware v4.0 and above for full RTD support. For v3.x, RTD inputs may be partially disabled—confirm compatibility before purchasing.