GE 151X1207CK02SA02 SCR 4400 V 1850 A IS200EDEXG1ADA General Electric EX2100



GE 151X1207CK02SA02 (77mm De-Excitation SCR Assembly) coupled with the IS200EDEXG1ADA (Exciter De-Excitation Control Board) form a high-power field discharge and de-excitation subsystem for General Electric EX2100 Excitation Control Systems.

Designed for utility-scale gas, steam, and hydro turbine generators, this assembly rapidly dissipates stored rotational energy and generator field energy during normal shutdowns or emergency trip conditions.

Product Overview

Integrated Power & Logic: Combines a high-voltage, high-current SCR power stack (151X series, 4400 V / 1850 A) with precise gate firing and conduction feedback logic (IS200EDEX board).

Rapid Field Energy Dissipation: Provides a controlled low-impedance conduction path through discharge resistors to protect generator rotor windings from overvoltage during an emergency trip.

Advanced Conduction Sensing: Utilizes integrated Hall-effect sensors and diagnostic feedback on the IS200EDEXG1ADA board to continuously monitor SCR firing and current decay.

Fault Tolerance: Built-in voltage retention logic maintains control state during power dips to guarantee reliable de-excitation.

Technical Specifications

Environmental Tolerance Conditions

Operating Temperature: -20°C to +60°C (-4°F to +140°F)

Storage Temperature: -40°C to +85°C (-40°F to +185°F)

Relative Humidity: 5% to 95% (non-condensing)

Contamination Level: ANSI/ISA-71.04 Class G3 harsh environment coating on PCB assembly

Cooling Requirements: Forced air cooling across the SCR heat sink fins during continuous system standby/operation

Operating Instructions

Mechanical Mounting: Secure the 77mm SCR press-pack assembly using specified mounting clamp torque settings to maintain adequate thermal and electrical contact with heat sinks.

Wiring Connections: Connect the main power leads to the discharge resistor grid. Wire the gate drive and feedback harness from the IS200EDEXG1ADA board to the EXTB terminal board and 41 DC breaker auxiliary contacts.

Control Calibration: Configure de-excitation firing parameters and trip threshold levels within the GE Mark VI / Mark VIe / EX2100 software suite.

Conduction Check: Perform initial gate pulse tests and verify Hall-effect feedback signals prior to energizing the generator field.

Fault Diagnosis

Status indicators on the IS200EDEXG1ADA board and EX2100 system diagnostics display:

SCR Firing Failure: Caused by open/shorted gate leads, improper control signals from EXTB, or loss of 24 VDC power.

Conduction Sense Fault: Discrepancy between command signal and Hall-effect sensor current reading.

Overvoltage Trip: Automatic SCR firing triggered due to field voltage exceeding safe hardware limits.

Thermal Overload: Elevated SCR sink temperature resulting from extended discharge cycles or cooling fan failure.

Related Models (GE EX2100 / Excitation Series)

IS200EDEXG1AFA: De-Excitation Board (Alternative Revision / Group 1 SCR)

IS200EDEXG2ADA: De-Excitation Control Board for Diode-based De-excitation

IS200EGDMH1A: Exciter Ground Detection / De-Excitation Main Board

151X1207DC22SA05: 77mm Phase SCR Module

IS200EMIOH1A: Excitation Main I/O Board

Storage Conditions

Store in original anti-static ESD shielding bags inside climate-controlled facilities.

Maintain ambient temperatures between -40°C and +85°C with non-condensing humidity.

Protect press-pack SCR contact surfaces from physical impact, moisture, high oxidation, and corrosive chemical vapors.