GE IS200EXHSG4A

IS200EXHSG4A is an exciter high-speed relay driver board developed by GE. It is a part of EX2100 Excitation system. The Exciter High-Speed Relay Driver board is used in the EX2100 Excitation Control and provides drivers for the dc contactors (41) as well as pilot relays for field flashing and de-excitation. Through the Exciter Backplane Board, these boards connect to three Exciter Main Input/Output Boards (EMIO, redundant control) or one EMIO board (simplex control) (EBKP).

Features

On the board are pilot relays for the flashing relays 53A and 53B, as well as pilot relays for the de-excitation relay KDEP.
The Exciter De-Excitation Board (EDEX) de-excitation status signals are conditioned on EXHS and sent to EMIO. Crowbar status signals are conditioned on EXHS and sent to EMIO from the EXDE De-Excitation Control Board.
On EXHS, three contact inputs from 41, 53A, and 53B are powered by 70 V dc and their feedback is monitored. The contacts are powered by the exciter power supply. The status signals generated are sent to the EMIO.

Contact Inputs

Contacts 53A, 53B, and 41 are brought into EXHS for EMIO monitoring. The contact input uses are similar in the simplex and redundant cases; however, for redundant control, the inputs are fanned to the M1, M2, and C controllers.
Signals in simplex control are only routed to the EMIO in the M1 controller. The three contacts are wetted by EXHS's 70 V dc supply. Power is isolated and supplied to the contacts via resistors from plugs J12M1 and J12M2. The wetting voltage can range between 63 and 84 V dc.
The resulting signal is distributed to M1, M2, and C, while the contact input monitoring circuit is located on EMIO.

Application Data

The close function contactor drivers are K41 (M1, M2, C), and the flashing pilot relays are K53A and K53B.
The single de-excitation pilot relay is KDEP. J505, J508, and J515 are 25-pin connectors for cables to the EMIO boards M1, M2, and C. They carry similar signals and have similar wiring, with the exception that J505 is connected to M1, J508 is connected to M2, and J515 is connected to C.
However, J515 lacks de-excitation and crowbar signals. For auxiliary contact wetting, plugs J12M1 and J12M2 bring in 70 V dc from the M1 and M2 power supplies.

Board Replacement Procedure

Ensure that the exciter has been deactivated.
Inside the control cabinet, ensure that all electrical I/O circuits are turned off before touching them.
To simplify reconnection, ensure that all cables are labeled with the correct connector name (as marked on the board), then carefully disconnect all cables from the EXHS board. Before removing any mounting hardware, place a rag or other nonconductive barrier beneath the EXHS board (above the board rack). Dropping a clip or any hardware into the equipment could result in equipment damage, personal injury, or an exciter trip while the EX2100 is turned on.
Remove the screws holding the EXHS board to its mounting and the board itself.
Verify that the replacement board is the same type (G1 or G2) as the original one.
Install the new EXHS board on its mounting with the screws removed in step 4 and orient it in the same position as the one removed.
Reconnect all cables to the EXHS board as labeled, making sure they are properly seated on both ends. Shut the control cabinet door.
Functional Comparison-EXHSG4A vs. EXTB

EXHSG4A shares many similarities with the exciter terminal board. However, it differs significantly by replacing the forty-one DC contactors found on the EXTB with a solid-state relay driver. Additionally, this board features two conduction sensors, identified as E1 and E2.