GE IS200EAUXH1A EXCITER AUXILIARY I/O INTERFACE BOARD

TECHNICAL SPECIFICATIONS

Manufacturer: General Electric (GE) Industrial Systems

Series: EX2100e Excitation Control Series / Mark VI Speedtronic

Functional Acronym: EAUX (Exciter Auxiliary Interface)

Board Type: I/O Termination Board / Digital Controller

Product Status: Active – In-service

REDUNDANCY CONFIGURATION:

• Redundancy Type: TMR (Triple Modular Redundancy) supported

• Control Sections: M1, M2, C

• Simplex Variant: H2A designation replaces H1A for simplex configurations

POWER REQUIREMENTS:

• Operating Voltage: 24 Volts DC

• Wetting Voltage: 125 Volts DC

INPUTS AND OUTPUTS:

• Contact Inputs: 3

• Digital I/O: Configurable with support for multiple 24 VDC channels

• Contactors: 41DC specification

COMMUNICATION INTERFACES:

• HSSL (High-Speed Serial Link): 2.5 Mbps data rate for main control processor communication

• RS-485 Serial Interface

• Communication Protocols: Modbus, Profibus

PHYSICAL SPECIFICATIONS:

• Dimensions: 230 mm x 160 mm x 80 mm (Length x Width x Height)

• Weight: Approximately 6.3 kg (Approximately 4 lbs assembled)

• Cable Length: 0.6 meter twisted pair red/black cable

• Mounting: Direct backplane insertion on EBKP carrier

OUTPUT CHARACTERISTICS:

• Special Output: 41 Volts DC flashing output generated when connected to HSLA/HSSL interfaces

• Output Response Time: 1 millisecond I/O refresh cycle

ENVIRONMENTAL SPECIFICATIONS:

• Operating Temperature: -40°C to +85°C (Industrial wide temperature range)

• Storage Temperature: -40°C to +70°C

• Relative Humidity: 5% to 95% RH non-condensing

• Forced Air Cooling Required: 0°C to 60°C

• Without Forced Air Cooling: 0°C to 40°C

PROTECTION FEATURES:

• Isolation Voltage: 1500 Volts DC (channel to ground)

• IP67 Protection rating for terminal area

• Metal shielding enclosure with IP67 terminal cover

RELIABILITY SPECIFICATIONS:

• MTBF: ≥100,000 hours at 40°C full load

• Annual Failure Rate: <200 ppm

• Availability: 99.999% I/O availability in TMR configurations

INTERFACE CONNECTORS:

• 37-pin JR1 latching connector

• TB1 screw terminal block supporting #12 AWG wire

• JE connector for generator and line signal transmission

• 3PL connector for signal transmission to STCA boards

REGULATORY COMPLIANCE:

• Manual Reference: GEH-6781 Series Manual

• User Guide: GEA-S1302A EX2100e Excitation Control Guide for 100, 77, 53, and 42 mm Thyristor Systems

FUNCTIONAL FEATURES

High-Speed Serial Link Communication
The IS200EAUXH1A interfaces with the main control processor exclusively through a High-Speed Serial Link (HSSL) operating at 2.5 Mbps . This communication architecture enables complete I/O refresh cycles within 1 millisecond, achieving performance three times faster than traditional parallel bus systems. The HSSL interface satisfies the demanding 5-millisecond scan cycle requirements essential for proper excitation system operation .

Triple Modular Redundancy Support
The board is specifically engineered for TMR architectures where three identical modules operate in parallel . Within Mark VI TMR configurations, two IS200EAUXH1A boards are typically deployed together: one managing local contacts while the second handles remote trips . This redundant configuration ensures that system operation continues uninterrupted when any single module fails, maintaining SIL 2 integrity levels throughout component replacement procedures .

Field Ground Leakage Detection
The board facilitates the EXAM (External Auxiliary Module) connection to provide essential field ground detector functionality for the excitation system . This detection capability identifies ground faults in the generator field winding, enabling maintenance personnel to address insulation degradation before catastrophic failure occurs.

41 Volt DC Flashing Output
The IS200EAUXH1A generates a specialized 41 Volt DC flashing output when properly connected to HSLA and HSSL interface boards . This output is specifically designed for thyristor firing circuits, producing synchronized 50 Hz or 60 Hz pulses under HSSL command. The flashing output enables zero-crossing conduction in the power bridge, reducing excitation harmonics by 8% compared to standard implementations .

Signal Conditioning and Processing
The board performs comprehensive signal conditioning for various excitation system inputs including voltage measurements, current monitoring, temperature sensing, and switch state signals . Collected signals are processed, converted to digital format, and transmitted to the main controller for closed-loop regulation algorithms. The board achieves 12-bit resolution with 0.1% accuracy across input ranges .

Configurable Digital I/O Architecture
Eight channels of 24 VDC digital I/O are available and configurable online as inputs, outputs, or pulse mode operations . This single-board configurability replaces two traditional relay modules, reducing cabinet space requirements by 30%. The design supports both sink and source configurations for maximum application flexibility.

Optical Isolation and Noise Immunity
The board implements 1500 Volt DC opto-isolation between channels and ground, completely eliminating ground loop interference . This isolation enables reliable operation over long cable runs and within electrically noisy industrial environments. The industrial-grade design features robust noise rejection for stable system operation even under severe electromagnetic interference conditions .

Hot-Swap Maintenance Capability
The module supports online replacement without powering down the remaining rack components . Hot-swap capability reduces Mean Time To Repair to less than five minutes, minimizing production downtime during preventive maintenance activities. The average module replacement requires less than two minutes in TMR configurations .

Wide Environmental Tolerance
The board operates across an extended industrial temperature range from -40°C to +85°C, supporting deployment in diverse climate conditions . The IP67-rated terminal area provides protection against dust ingress and temporary water submersion. Metal shielding and conformal coating protect against sulfur corrosion and salt spray for offshore and coastal installations .

Multi-Protocol Communication Support
The board supports multiple industrial communication protocols including Modbus RTU and Profibus DP . This protocol flexibility enables straightforward integration with third-party systems, historians, and supervisory control platforms without requiring additional gateway hardware.

APPLICATION SCENARIOS

Gas Turbine Excitation Control
The IS200EAUXH1A is deployed extensively in GE 9F and 9E series gas turbine excitation systems . Within the turbine start-up cabinet, the board serves as the high-reliability interface for exciter contacts, temperature switches, and purge valve status monitoring. The module transmits 24 VDC logic signals to the main controller in real time, enabling 0% to 100% stepless regulation of excitation current. The fast 1-millisecond I/O refresh ensures stable excitation during turbine acceleration, load changes, and grid fault ride-through events .

Steam Turbine Generator Excitation
Industrial steam turbine applications use the IS200EAUXH1A for generator field excitation control in cogeneration facilities, combined cycle power plants, and conventional thermal stations . The board processes voltage regulator feedback, power factor correction signals, and synchronizing inputs essential for grid interconnection. The TMR configuration ensures continuous excitation availability during routine maintenance of individual control paths.

Hydroelectric Generator Systems
Hydro turbine applications benefit from the board wide temperature tolerance and field ground detection capabilities . The 1500 Volt isolation protects sensitive control electronics from the transient voltages common during generator breaker operations. The RS-485 interface supports remote monitoring of excitation parameters from centralized control rooms located significant distances from the turbine hall.

Combined Cycle Power Plants
In combined cycle facilities, the IS200EAUXH1A coordinates excitation control across both gas turbines and steam turbines . The multi-protocol communication support enables data sharing between different control system generations. The board processes plant-wide power factor commands, voltage setpoints, and reactive power distribution signals maintaining grid stability requirements.

Industrial Generator Sets
Emergency generators, standby power systems, and prime power installations utilize the board for excitation control . The hot-swap capability allows maintenance without shutting down critical facilities. The compact single-slot design fits within space-constrained generator control cabinets typical of industrial installations.

Field Excitation System Retrofits
The EX2100e series board is used for upgrading legacy excitation systems to modern digital control platforms . The enhanced technology indicated by the e suffix in EX2100e provides improved performance over standard EX2100 systems. The board compatibility with existing thyristor bridges simplifies retrofit projects while delivering digital control precision.

Offshore Power Generation
Oil and gas platforms with onboard power generation benefit from the board IP67 terminal protection and corrosion-resistant construction . The wide operating temperature range accommodates unheated equipment rooms in North Sea and Gulf of Mexico installations. The -40°C storage capability supports equipment stockpiling for remote offshore logistics.

Emergency Diesel Generator Excitation
Nuclear facilities, data centers, and critical infrastructure sites with emergency diesel generators employ the board for excitation control . The high reliability design with MTBF exceeding 100,000 hours supports mission-critical backup power applications. The TMR configuration with SIL 2 integrity satisfies safety-related control requirements.

SYSTEM INTEGRATION NOTES
The IS200EAUXH1A mounts directly to the EBKP backplane within the EX2100e excitation system rack . Connection to the UCSx controller is accomplished through an HSSL module interface . When connecting HSLA and HSSL boards simultaneously, the EAUX board generates the 41 VDC flashing output required for thyristor firing circuits . The simplex version of this board carries the H2A designation in the part number rather than H1A for non-redundant applications .

COMPATIBLE COMPONENTS

• UCSx Controller (via HSSL Module)

• EBKP Backplane

• HSLA High-Speed Serial Link Interface Board

• HSSL High-Speed Serial Link Board

• EXAM Board for Field Ground Detection

• GE 37-pin JR1 Connector

REFERENCE DOCUMENTATION

• GEH-6781 Series Manual

• GEA-S1302A EX2100e Excitation Control User Guide