Description Key Technical Specifications Parameter Specification Part Numbers DS200DCFBG2BNC, DS200DCFBG1BNC Product Type DC Field Bridge Board Series Mark V / EX2000 Drive Systems Function SCR firing control for DC motor field excitation Input 3-phase AC (voltage varies by application) Output Controlled DC to field windings Control Signals ±10V DC reference from regulator Feedback Current feedback isolation amplifiers Protection Overcurrent sensing, transient suppression Mounting Mounts in Mark V drive cabinet (power cage) Connectors Multiple pin headers, fiber optic (on some variants) Indicators Status LEDs for power, firing, faults Coating Conformal coated for industrial environment Condition New Surplus (Original Packaging) Product Introduction The GE DS200DCFBG2BNC and DS200DCFBG1BNC are DC field bridge boards used in GE Mark V drive systems. These boards control the SCR firing circuits that provide regulated DC excitation to DC motor fields. They take low-level control signals from the regulator section and convert them to properly timed gate pulses for the power SCRs in the field bridge. The DS200DCFBG1BNC represents an earlier revision, while the DS200DCFBG2BNC includes component updates and enhanced protection circuitry. Both boards include current feedback isolation and fault monitoring. These units are new surplus, factory-sealed in original GE packaging. Mark V drive components remain critical for heavy industry; contact us for current stock and firm pricing. Frequently Asked Questions (FAQ) Q: What’s the actual difference between DS200DCFBG1BNC and DS200DCFBG2BNC? A: The DS200DCFBG1BNC is the earlier design; the DS200DCFBG2BNC is a functional upgrade. From field experience, the -2 version includes: Improved transient suppression on feedback circuits Updated component sourcing (some original parts went EOL) Enhanced gate drive timing accuracy Better noise immunity on firing circuits Physically, they’re interchangeable in the same mounting location. The DS200DCFBG2BNC is generally preferred for replacements because it addresses known failure modes of the -1 version. However, always verify with your system documentation—some very old Mark V cabinets may require the exact revision. Q: Can I replace a DS200DCFBG1BNC with a DS200DCFBG2BNC without modifications? A: Yes, in most cases. The DS200DCFBG2BNC is designed as a drop-in replacement for the DS200DCFBG1BNC. The connector pinouts are identical, and the mounting holes align. However, you should: Verify jumper settings match between boards (take photos before removal) Check that firing circuit calibration pots are set correctly (may need minor tuning) Test at low field current first I’ve done dozens of these swaps in steel mills and paper machines. The works fine, but never assume—always verify. The drive doesn’t care which revision as long as signals match. Q: What does this board actually control in a DC drive system? A: The GE DS200DCFBG2BNC controls the motor’s field excitation—the stationary magnetic field that interacts with the armature current. In a DC motor, speed and torque depend on both armature voltage and field current. This board: Receives a field current reference from the main regulator Fires SCRs in the three-phase bridge to produce controlled DC Monitors actual field current via feedback Reports faults if field current deviates Without this board, the motor field gets no excitation—motor won’t turn, or if it does, it runs uncontrolled. The is essential for proper DC motor operation in Mark V systems. Q: What are the common failure modes for these boards? A: From years in the field: SCR gate drive transformers fail open. These tiny transformers couple firing pulses to the SCRs. Thermal stress kills them. Feedback isolation amplifiers drift or fail, causing incorrect current readings. Capacitors dry out—the board runs hot in enclosed cabinets. Transient damage from field flashovers or power line surges. The addressed some of these with better components, but it’s still a power electronics board in a harsh environment. If you see “Field Loss” faults or erratic field current, suspect this board. In one steel mill, we replaced three boards before the -2 version solved chronic failures. Q: Does this board require programming or configuration? A: No software programming—it’s an analog firing board. But it does have hardware configuration: Jumper settings for field voltage range Potentiometers for current feedback scaling Possibly DIP switches for response tuning When replacing either or , set jumpers exactly as the old board. Mark each pot position before removal (count turns). If you lose settings, you’ll need the drive prints and calibration procedure. This isn’t plug-and-play—it’s careful transfer of hardware settings. Q: Can I test this board out of the drive cabinet? A: Partially. You can check: Power supply voltages at test points SCR firing pulses with an oscilloscope (requires low-voltage test setup) Feedback circuit response with injected signals But full testing requires the board mounted in the drive with proper AC power and load. The GE DS200DCFBG2BNC interacts with the power SCRs and field winding—you can’t simulate that on a bench easily. In practice, we test by substitution: swap in a known-good board and see if the problem moves. Q: What’s the difference between DCFB and DCFG boards? I’ve seen both designations. A: DCFB (DC Field Bridge) and DCFG (DC Field Gating) are related but different. The combines both functions—bridge control and gating. Some older GE drives used separate boards: one for gating signals, one for feedback. The integrated these functions. By the time Mark V evolved, the combo board was standard. If you’re working on an older drive, verify which board your system uses. The may not be a direct replacement for a two-board system. Q: What kind of maintenance does this board require? A: Minimal, but critical: Keep connectors clean—oxidation causes intermittent firing Check for bulging capacitors during annual inspections Verify all mounting screws tight—loose grounds cause noise Monitor field current readings for drift (indicates feedback issues) The GE DS200DCFBG2BNC is generally “fit and forget” until it fails. But in dirty environments (cement plants, steel mills), conformal coating helps but doesn’t prevent all contamination. If you see carbon tracking or corrosion, replace proactively. Field failures cause unplanned downtime—expensive in continuous process industries. Q: Can I use this board in a Mark VI system? A: No. Mark VI drives use completely different architecture—different backplane, different power levels, different control interface. The is specific to Mark V and some EX2000 systems. Mark VI uses integrated drive modules with different part numbering. Don’t try to adapt—it won’t fit electrically or mechanically. Check your drive series before ordering. If you have Mark VI, you need Mark VI-specific field control boards. Q: What’s the typical lifespan of these boards in continuous operation? A: In a clean, temperature-controlled environment, 15-20 years. In typical industrial settings (steel, paper, mining), expect 10-15 years before component failures begin. The had shorter lifespan due to early component selections. The improved that. But both are ultimately limited by electrolytic capacitor life and thermal cycling. If your board is over 15 years old and still running, you’re on borrowed time. Keep a spare on the shelf—when it fails, production stops. 62P-MDF-0240-T-0-00 PLC 62-PMDF-0360-TB-68 PLC PM150V08 PLC MVME133XT PLC SHOWASCM-DTU2 PLC 2711P-RDT10CX PLC Email: [email protected] Phone: 86 15340683922 Sales:Wu Jiedong Our products are guaranteed for 1 year, with new and original production stopped and imported spare parts. All prices listed on the official website are subject to confirmation by contact: Wu Jiedong (manager). Our product: brand new original packaging Our warranty: All new or repaired parts have a 12 month warranty period beginning Our payment: 100% telegraphic transfer of inventory items before shipment, conditions can be proposed! 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