GE DS3800NHVM1B1A

Key Technical Parameters

Advantages and Distinctive Features

• Highest Relay Current (3A @ 125VDC): Delivers 3A continuous (6A surge)—the highest current capacity of any high-voltage DC fan board in the Mark V lineup.

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

• 24-Bit Ultra-High Precision ADC: ±0.5°C for thermocouples, ±0.3°C for RTDs.

• Predictive Relay Maintenance: Real-time contact resistance monitoring with relay degradation warning.

• Hybrid Output + Tachometer Feedback: Combines 8 high-voltage DC relay outputs, 4 high-current solid-state outputs, AND 2 tachometer inputs.

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

• 200-Event Fault Log: Comprehensive diagnostics.

Typical Application Fields

• High-Power 125VDC Cooling Systems: Where 3A @ 125VDC capacity is required for large exhaust fans.

• Safety-Critical Cooling Systems: With redundant temperature sensing and fan failure detection.

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

• Legacy Turbine Installations: Older systems requiring both T/C and RTD monitoring.

Comparison with Related Models

Selection Recommendations

• Choose the DS3800NHVM1B1A if:

  • You need the highest 125VDC relay current (3A) for powerful exhaust fans.

  • You need high-current solid-state outputs (3A @ 48VDC) .

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

  • You require tachometer feedback for fan speed verification.

  • You want predictive relay maintenance.

  • You need 24-bit ADC accuracy.

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

• Choose the full DS3800NHVM if: You need the same features but with extreme temperature tolerance (-40°C to +75°C) and 500-event logging.

• Choose the DS3800NHVL1C1C if: You only need 4 thermocouple + 8 RTD inputs (12 channels) with extreme temperature tolerance.

Critical Precautions

• ESD Protection: Always wear a grounded wrist strap. Static damage to the 24-bit ADC degrades accuracy.

• High-Voltage Hazard: Relay outputs switch 125VDC—lethal voltage present on terminals. Observe all high-voltage safety procedures. Use wiring rated for ≥125VDC.

• 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.

• DC Polarity (Relay): Relay outputs are DC only—observe correct polarity.

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

• Tachometer Wiring: Use shielded twisted-pair cable. Connect shield to designated terminal.

• Relay Current Limitation: Rated at 3A continuous @ 125VDC. Verify fan current does not exceed this limit.

• SS Current Limitation: Rated at 3A continuous @ 24–48VDC.

• Inductive Load Derating (Relay): For inductive fan motors, derate to 2A or use external RC snubbers (rated for 125VDC).

• No AC Connection: Do not connect AC loads to either output type.

• 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—all advanced features disabled in fallback mode.

• Firmware Compatibility: The DS3800NHVM1B1A requires Mark V CPU firmware v5.0 or higher for full 24-bit ADC, predictive maintenance, and RTD support. For v4.x, the board reverts to 16-bit mode with no predictive maintenance.

• Power Supply: Draws 5.5A on +5V rail—a power supply upgrade is mandatory for most installations.