IS200EDEXG1A

IS200EDEXG1A is an Exciter De-Excitation Board manufactured by General Electric as a part of the EX2100 series used in Excitation control systems. IS200EDEXG1A serves as the primary PCB in an EX2100 De-Excitation Module, allowing conduction sensing feedback, voltage retention during power outages, and de-excitation firing. The EPSM module, which converts 125VDC to 24VDC, provides power to the board. In the de-excitation module, the EDEX board is the main board. To assure operation in the event of a power outage, EDEX provides de-excitation SCR firing, conduction sense feedback, and voltage retention. On the EXTB board, EMIO initiates de-excitation. The EXTB board opens the 41 DC contractor (41A/41B) or breaker, then passes the excitation signals from the auxiliary contacts to the EDEX's SCR firing circuits. EDEX is divided into two categories. The Group 1 board is for SCR de-excitation, while the Group 2 board is for diode de-excitation. EDEX is usually controlled by EXTB but can initiate de-excitation if control fails.