Description
DS3800NBIB1K1E Product Overview
The DS3800NBIB1K1E is a bridge-interface and current-isolator board used inside GE Mark IV turbine and EX2000 exciter control racks. It occupies a mid-rack slot on the 6BA Euro-card file and performs three critical functions:
The DS3800NBIB1K1E is a bridge-interface and current-isolator board used inside GE Mark IV turbine and EX2000 exciter control racks. It occupies a mid-rack slot on the 6BA Euro-card file and performs three critical functions:
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Gate-Drive Interface – It converts 5 V logic pulses from the CPU into ±15 V isolated gate pulses and delivers them to the SCR or IGBT bridge via fiber-optic ST ports.
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Feedback Scaling – It scales armature-voltage and bridge-current signals (480 V class) down to ±10 V so the 5 V CPU A/D converters are protected from high-voltage transients.
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Current Isolation – It provides 1500 Vdc channel-to-ground isolation, ensuring that a shorted power device cannot drag the control logic down with it.
All copper traces are fully encapsulated in high-temperature epoxy, making the unit non-repairable—any internal fault requires a complete card swap rather than component-level rework. The module is fully hot-swappable when the rack is powered down, and its 1.0 lb weight allows adjacent-slot population without additional support brackets.
GE DS3800NBIB1K1E
DS3800NBIB1K1E Technical Specifications
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Model Number: DS3800NBIB1K1E
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Manufacturer: General Electric
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Product Type: Bridge Interface / Current Isolator Board
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Series: DS3800, Mark IV / EX2000 Speedtronic
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Form Factor: 6BA Euro-card (≈ 233 × 160 mm)
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Back-Plane Connector: Dual 40-pin header (J1/J2)
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Gate Outputs: 6 × fiber-optic ST ports, 15 mA @ 820 nm
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Analog Inputs: 12 differential ±10 V (armature volts, bridge current)
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Isolation: 1500 Vdc channel-to-ground; 2.5 kV optical on fibers
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Power Demand: +5 V @ 0.8 A, ±15 V @ 0.3 A from rack 2PL bus
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Operating Temperature: 0 – 60 °C
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Weight: 1.0 lb (≈ 0.45 kg)
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Construction: Epoxy-sealed copper traces—non-repairable
Core Features & Customer Value
Integrated Gate & Feedback Interface: By combining gate-drive generation and high-voltage feedback scaling on one card, the module eliminates separate gate amplifiers and signal conditioners. For the maintenance crew this means fewer spare part numbers to stock and a single five-minute swap instead of troubleshooting three separate boards.
Epoxy-Sealed Construction: All internal copper is encapsulated in high-temperature epoxy. In environments with high humidity, dust, or conductive contamination the seal prevents trace-to-trace shorting that would otherwise cause random “BRIDGE INTERFACE FAIL” alarms after ten-plus years of service. The trade-off is non-repairability—any internal fault requires a whole-card exchange—but this is offset by the reduced diagnostic time and the fact that plants stock one spare instead of maintaining a repair bench.
Fiber-Optic Gate Drive: The six ST fiber ports deliver ±15 V isolated gate pulses with <1 µs skew. For the power electronics engineer this means the six-pulse SCR or IGBT bridge fires in perfect phase sequence, minimizing harmonic distortion and preventing shoot-through that would otherwise destroy the power semiconductors.
GE DS3800NBIB1K1E
Typical Applications
In combined-cycle power plants the board is installed in the Mark IV exciter cubicle where it provides the gate-drive interface for the six-pulse SCR bridge. During a black-start the card ramps field current from zero to rated value over a user-defined curve, preventing over-fluxing of the generator stator. The 12 analog inputs also monitor bridge volts and armature current in real time.
On mechanical-drive gas compressors the same module is used to fire the variable-speed drive IGBT stack. The on-board MOV string clamps lightning-induced surges on the 480 VAC feeder, while the scaled ±10 V feedback signals allow the CPU to compute firing angle without additional signal-conditioning hardware. Because the card is line-replaceable, a surge event that damages any internal layer is corrected with a five-minute swap rather than a half-shift re-cabling job.
