Description
DS3800HLIA1A1B: Product Overview
This board occupies a 6BA Euro-card slot in GE Mark IV turbine and EX2000 exciter control racks, serving as a high-voltage input interface for monitoring AC and DC power system status. It accepts 120 Vac or 240 Vac/Vdc signals directly from station batteries, breaker auxiliary contacts, or mains presence indicators, provides 2500 Vdc isolation to protect the 5 V CPU from high-voltage transients, and buffers the conditioned signals to the NDIA data bus. The “HLIA” designation indicates high-level input auxiliary functionality, while the A1B revision includes enhanced surge protection for direct connection to station battery circuits without external interposing relays.
This board occupies a 6BA Euro-card slot in GE Mark IV turbine and EX2000 exciter control racks, serving as a high-voltage input interface for monitoring AC and DC power system status. It accepts 120 Vac or 240 Vac/Vdc signals directly from station batteries, breaker auxiliary contacts, or mains presence indicators, provides 2500 Vdc isolation to protect the 5 V CPU from high-voltage transients, and buffers the conditioned signals to the NDIA data bus. The “HLIA” designation indicates high-level input auxiliary functionality, while the A1B revision includes enhanced surge protection for direct connection to station battery circuits without external interposing relays.
The epoxy-sealed construction makes this a line-replaceable module—internal faults require complete card swap rather than field repair. The module hot-swaps when the rack is powered down, and its low profile allows adjacent-slot population without additional cooling. As part of the DS3800 family, it benefits from the Mark IV platform’s deterministic 2 ms control interval and extensive installed base in power generation applications.
DS3800HLIA1A1B
DS3800HLIA1A1B: Technical Specifications
-
Model Number: DS3800HLIA1A1B
-
Manufacturer: General Electric (GE Fanuc)
-
Product Type: High-Level Input Auxiliary / High-Voltage Input Board
-
Series: DS3800, Mark IV Speedtronic
-
Form Factor: 6BA Euro-card (≈ 233 × 160 mm)
-
Back-Plane Connector: Dual 40-pin header (J1/J2)
-
Input Voltage: 120 Vac or 240 Vac/Vdc (jumper-selectable per channel)
-
Input Impedance: 100 kΩ nominal (minimizes loading on monitored circuits)
-
Isolation: 2500 Vdc channel-to-ground; opto-coupled inputs
-
Update Rate: 2 ms (synchronized to CPU scan)
-
Threshold Accuracy: ±5 % of nominal (A1B improvement)
-
Surge Protection: 40 mm MOVs and gas discharge tubes (A1B enhancement)
-
Power Demand: +5 V @ 0.4 A, +15 V @ 0.2 A from rack 2PL bus
-
Operating Temperature: 0 – 60 °C
-
Weight: ≈ 0.28 kg
-
Construction: Epoxy-sealed copper traces—non-repairable
Core Features & Customer Value
Direct High-Voltage Monitoring: The 2500 V isolation and 240 V input capability eliminate external potential transformers or interposing relays for battery and mains monitoring. For panel designers, this reduces component count, wiring complexity, and failure points while saving 40-50% of the space required for traditional high-voltage input schemes.
Enhanced Surge Protection: The A1B revision includes cascaded MOVs and gas discharge tubes rated for station battery switching transients. For maintenance teams, this extends card life in electrically harsh environments where inductive kick from battery breakers can exceed 2 kV.
Epoxy-Sealed Construction: All internal copper is encapsulated in high-temperature epoxy. In coastal or industrial environments with conductive dust and high humidity, this prevents trace-to-trace shorting that would cause false “BATTERY FAIL” or “MAINS LOSS” alarms after ten-plus years. The trade-off is non-repairability—internal faults require whole-card exchange—but this is offset by reduced troubleshooting time and single-spare stocking rather than maintaining a repair bench.
DS3800HLIA1A1B
Typical Applications
In combined-cycle power plants, this board installs in the Mark IV turbine control core where it monitors 125 Vdc station battery presence, 480 Vac auxiliary mains status, and emergency diesel generator breaker position. The direct high-voltage input eliminates auxiliary relays that would otherwise be required for each monitored point.
On utility-scale EX2000 static exciters, the same card tracks the 250 Vdc field battery status and the exciter breaker auxiliary contacts. The enhanced surge protection is critical here—field breaker operation generates transients that destroy unprotected electronics.
Mechanical-drive gas compressors in remote pipeline stations frequently use this part number to monitor the 24 Vdc control battery (via voltage divider) and the local utility mains presence. The high input impedance minimizes battery loading, preventing the monitoring circuit itself from causing low-voltage alarms.
