GE DS3800NGRA1B1A

Key Technical Parameters

Advantages and Distinctive Features

• 5A Mechanical Relay Outputs: The DS3800NGRA1B1A delivers 5A continuous output capability (10A surge), making it suitable for driving 1/2 HP AC fans or multiple DC fans in parallel.

• Improved Temperature Accuracy (16-bit ADC): Provides ±1°C accuracy—double the precision of the base 12-bit (±2°C) model—enabling better thermal management.

• AC/DC Output Capability: Can switch both AC and DC fan loads, offering flexibility for mixed cabinet installations.

• Complete Galvanic Isolation: Relay outputs provide 2500V isolation between control logic and fan power circuits.

• Full 8 Thermocouple Inputs: Comprehensive zone-by-zone temperature monitoring for large cabinets.

• Enhanced Firmware (Revision B): Improved cold-junction compensation for more reliable temperature readings.

Typical Application Fields

• Turbine Cabinets with Large AC Fans: Where 5A relay capacity is required for 1/2 HP blowers or multiple fans per channel.

• Climate-Controlled Indoor Installations: 0°C to +60°C range supports standard power plant environments.

• High-Surge Fan Applications: Mechanical relays handle startup surges better than solid-state alternatives.

• Retrofit Upgrades: Replacing base DS3800NGRA boards with the DS3800NGRA1B1A for improved temperature accuracy.

• Budget-Conscious Higher-Current Applications: Cost-effective solution without tachometer feedback.

Comparison with Related Models

Selection Recommendations

• Choose the DS3800NGRA1B1A if:

  • Your fans require mechanical relay outputs with 5A continuous rating.

  • You do not require tachometer speed feedback.

  • You want improved temperature accuracy (±1°C) for better thermal management.

  • Your cabinet requires 8 temperature sensors for comprehensive monitoring.

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

  • The Mark V CPU handles all control logic.

  • You are upgrading from a base DS3800NGRA for better performance.

• Choose the DS3800NFLA1C1C if: You need 5A relays with tachometer feedback and extended temperature range (-20°C to +65°C) but can accept 4 thermocouple inputs.

• Choose the DS3800NGDC1A1A if: You need 3A relay outputs with basic 12-bit ADC.

• Choose the base DS3800NGRA if: You do not require improved temperature accuracy.

Critical Precautions

• ESD Protection: The DS3800NGRA1B1A contains sensitive ADC components. Always wear a grounded ESD wrist strap.

• Relay Contact Wear: Mechanical relays are rated for 100,000 operations at 5A. For frequent cycling applications, consider derating or using solid-state alternatives.

• Inductive Load Derating: The 5A rating applies to resistive loads. For inductive fan motors, derate to 3.5A or use an external RC snubber across each relay output.

• No Tachometer Inputs: The DS3800NGRA1B1A has no tachometer capability. Do not connect speed sensors.

• No Hot-Swap: Always depower the Mark V rack before inserting or removing the DS3800NGRA1B1A.

• Slot Assignment: Install in auxiliary I/O slots (typically slots 8–10). Do not install in CPU or analog input slots.

• CPU Dependency: Since the DS3800NGRA1B1A has no onboard logic, the Mark V CPU must send fan ON/OFF commands. If backplane communication is lost, the board defaults to 100% fan speed (fallback mode). Address communication issues promptly.

• Firmware Compatibility: Revision B firmware on the DS3800NGRA1B1A is compatible with Mark V CPU firmware v4.0 and above. For v3.x systems, the enhanced ADC accuracy may be partially disabled. Confirm compatibility before purchasing.