De-Excitation Board GE IS200EDEXG1BBB

Configured for generator field energy dissipation in Mark VI Speedtronic excitation systems, the GE IS200EDEXG1BBB (IS200EDEX De-Excitation Board) provides direct physical execution of crowbar switching and overvoltage suppression tasks within the turbine control network.

Hardware Specifications

Backplane Bus and Firmware Execution Characteristics

The IS200EDEXG1BBB interfaces directly with the Mark VI VME backplane bus, supporting deterministic command execution for field breaker trip sequencing. Firmware flash compatibility is maintained exclusively within the Mark VI architecture; cross-series loading into Mark V or Mark VIe hardware is unsupported. Licensing for advanced excitation profiles is pre-bound to the board’s EEPROM identifier, preventing unauthorized firmware substitution.

Frequently Asked Questions

Q: Can the IS200EDEXG1BBB be hot-swapped without turbine shutdown?

A: No. Physical removal requires complete de-energization of the excitation cubicle to prevent arc exposure on the field discharge contacts.

Q: Does the board support redundant operation in parallel excitation systems?

A: Yes, but only when installed in separate racks with independent power feeds; no onboard TMR logic exists.

Q: What is the expected backplane current load during steady-state operation?

A: Approximately 1.5 A at 24 VDC excluding external contactor coil loads.

Field Installation Guidelines

Mount the IS200EDEXG1BBB vertically in the designated VME slot to ensure optimal forced-air cooling. Use torque-controlled fastening for terminal blocks (recommended 0.8 Nm). Maintain separation between high-voltage field wiring and low-voltage control cables to minimize inductive coupling. Ground the excitation chassis to the plant ground grid with a minimum 35 mm² copper conductor. Verify isolation resistance (>10 Mohm) between field terminals and logic ground before energizing.