DS3800DXRA1C1C GE

Technical Specifications

• Product Type: Digital Expansion Relay & Alarm Board (Revision 1C1C)

• Part Number: DS3800DXRA1C1C

• Manufacturer: General Electric (GE)

• System Compatibility: GE Speedtronic Mark IV Turbine Control Systems (Rev. M and later)

• Output Channels: 16 digital outputs (Form C – SPDT relays)

• Contact Rating: 5A @ 250VAC or 5A @ 30VDC (resistive); 3A @ 250VAC (inductive – upgraded)

• Surge Suppression: Enhanced RC snubbers + bidirectional TVS diodes (upgraded from standard flyback)

• Indicators: Front-panel LEDs per channel

• Isolation: 2500Vrms reinforced opto-isolation (upgraded from 1500Vrms)

• Expansion Interface: Backplane slave connection; address configurable via DIP switches

• Temperature Range: -40°C to +70°C (extended)

• MTBF: > 200,000 hours (MIL-HDBK-217F)

Key Features & Advantages

• Enhanced Surge Suppression: The GE DS3800DXRA1C1C uses RC snubbers and bidirectional TVS diodes, providing superior protection against inductive load transients compared to earlier revisions.

• Higher Inductive Load Rating: Rated 3A inductive (vs. 2A on earlier versions), suitable for larger solenoids and contactors.

• Reinforced Isolation: Upgraded to 2500Vrms, protecting against ground loops and voltage transients.

• Extended Temperature Range: -40°C to +70°C for outdoor or unheated turbine enclosures.

• Slave Expansion: Adds 16 relay outputs without occupying a processor slot.

• Form C Contacts: Each channel provides both NO and NC contacts for flexible configuration.

• Flexible Addressing: DIP switch configuration for easy address assignment.

• Diagnostic LEDs: Front-panel status indication per channel.

Typical Application Cases

• Alarm Annunciation Expansion: Adds extra alarm channels for detailed turbine status reporting.

• Additional Control Outputs: Provides outputs for auxiliary equipment (fans, heaters, lighting).

• Remote Signaling: Sends additional status signals to plant DCS or SCADA.

• Interlock Logic: Extra relay contacts for safety interlocks and permissives.

• Harsh Environment Installations: Extended temperature range suits offshore, arctic, or desert sites.

Competitive Comparison

The GE DS3800DXRA1C1C offers significant improvements over earlier revisions in protection, load capacity, and environmental tolerance, making it the preferred choice for demanding applications.

Selection Guidelines & Precautions

1. Channel Count: Confirm required additional outputs. Multiple DS3800DXRA1C1C boards can be installed.

2. Processor Compatibility: Requires Mark IV processor Rev. M or later. Verify firmware compatibility before installation.

3. Address Configuration: Set DIP switches correctly to avoid backplane address conflicts. Refer to Mark IV manual.

4. Contact Current: Confirm load does not exceed 5A resistive or 3A inductive. Use external interposing relays for larger loads.

5. Wiring: Use shielded cables; ground shield at board end only.

6. TVS Diode Orientation: The bidirectional TVS diodes are polarity-insensitive; no orientation required.

7. ESD Handling: Use ESD-safe practices.

8. Sourcing: Obsolete. Request functional test report including:

   • All 16 channels tested under rated load (resistive and inductive)

   • Contact resistance (< 0.1Ω new, < 0.5Ω refurbished)

   • Surge suppression verification (RC + TVS functionality)

   • Isolation test (2500Vrms)

   • Address configuration validation

   • Temperature cycle test (if available)

9. Spare Strategy: Keep one spare GE DS3800DXRA1C1C on-site. For critical alarm circuits, consider redundant configuration using two boards. If unable to source this exact revision, the DS3800DXRA1A1A is a compatible alternative with lower specifications.