GE IS200EDEXG1BAA Exciter De-Excitation Control Board for Mark V

The GE IS200EDEXG1BAA is an Exciter De-Excitation Control Board (EDEX) in the EX2100e excitation system, critical for generator safety during emergency shutdowns. Its primary role is to dissipate stored energy from the generator field when field breakers or contactors open, preventing damage.

Integral to the de-excitation module, it works with the EMIO and EXTB boards to trigger and execute energy dissipation via controlled Silicon Controlled Rectifier (SCR) firing. Equipped with Hall Effect conduction sensors, voltage hold-up circuits, and status LEDs, it ensures reliable operation even during power failures.

• SCR Control: Manages SCR firing to regulate current flow and efficiently dissipate generator field energy during shutdowns.
• Conduction Feedback: Uses Hall Effect sensors with a magnetic coupling ring to detect bipolar current flow, transmitting signals M1/M2 to the EXTB board for monitoring and control.
• Voltage Retention: A hold-up circuit maintains ±24V DC rails during power failures, ensuring SCR firing and external contact functionality for uninterrupted de-excitation.
• EMIO Initiation: Triggered by the EMIO board via the EXTB, it coordinates contactor/breaker opening and signal transfer to SCR circuits.
• Status Indicators: Two red LEDs illuminate during current detection, providing visual feedback on conduction sensor operation for diagnostics.