Description
DS3800NPSF1C1B Product Overview
The DS3800NPSF1C1B is a power-supply firing board used inside GE Mark IV and EX2000 turbine control racks. It occupies a 6BA Euro-card slot and performs three essential functions:
The DS3800NPSF1C1B is a power-supply firing board used inside GE Mark IV and EX2000 turbine control racks. It occupies a 6BA Euro-card slot and performs three essential functions:
-
Gate-Drive Generation – It receives 5 V CMOS fire pulses from the CPU and boosts them to ±15 V isolated gate signals, delivered to the SCR or IGBT bridge via fiber-optic ST ports.
-
Field Power Distribution – It converts raw 120–240 VAC control power into a regulated +24 Vdc field bus (3 A) for contactor coils and auxiliary relays.
-
Surge Clamping – On-board 40 mm MOVs absorb lightning or switching transients, preventing damage to downstream logic cards.
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 1.5 lb weight allows adjacent-slot population without additional support brackets.
DS3800DFXB1B1C
DS3800NPSF1C1B Technical Specifications
-
Model Number: DS3800NPSF1C1B
-
Manufacturer: General Electric
-
Product Type: Power-Supply Firing / Gate-Drive Interface Board
-
Series: DS3800, Mark IV / EX2000 Speedtronic
-
Form Factor: 6BA Euro-card (≈ 233 × 160 mm)
-
Back-Plane Connector: Dual 40-pin header (J1/J2)
-
Field Power Output: +24 Vdc @ 3 A (current-limited)
-
Gate Drive Output: ±15 Vdc isolated, 2 A peak per SCR/IGBT leg
-
Surge Protection: 40 mm MOVs, 1 kJ pulse rating
-
Isolation: 1500 Vdc input-to-logic; 2.5 kV optical on gate fibers
-
Operating Temperature: 0 – 60 °C
-
Weight: ≈ 1.5 lb (≈ 0.68 kg)
-
Construction: Epoxy-sealed copper traces—non-repairable
Core Features & Customer Value
Integrated Power & Gate Drive: By combining 24 V field supply and ±15 V gate drive on one card, the module eliminates separate power supplies and gate amplifiers. 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 “FIELD POWER 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.
Wide AC Input Window: The board accepts 120–240 VAC directly from the control transformer. This allows the same part number to be used on 120 V or 240 V services without additional taps or selectors, simplifying spares inventory and reducing wiring errors during retrofit projects.
DS3800DFXB1B1C
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 the 24 V contactor bus and the ±15 V gate supply in sequence, preventing the bridge from firing into an un-powered CPU.
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.
