Quick Sizing & Sourcing Snapshot

• Manufacturer:​ GE (General Electric)
• Part Number:​ IS200ESYSH3AAA (Base: IS200ESYSH3A)
• System Platform:​ EX2100 / EX2100e Excitation Control (Mark VI/VIe)
• Hardware Type:​ Excitation System I/O Terminal Board (ESYS – Simplex)
• Architectural Role:​ Provides the passive field termination for Generator PT/CT signals and Trip Relays, interfacing one control processor (M1) via HSLA (HSSL) daughter cards.
• Key Specifications:​ Simplex Mode, 2 Trip Relays, 7 Aux Contacts (55V DC), 6x D-Sub​ for HSLA.

System Architecture & Operational Principle

The is a passive terminal board located in the EX2100/EX2100e Exciter Cabinet, functioning as the field-facing I/O hub for a Simplex (Single Channel)​ control architecture. It is the “H3” variant, which specifically denotes Simplex Control​ operation, differing from H1 (TMR M1/M2/C) or H2 (Dual/Redundant) configurations.

Physically, it mounts to the cabinet framework. Upstream, it connects to a single M1 Controller​ (via EBKP backplane) using HSLA (High-Speed Serial Link)​ daughter boards plugged directly onto the ESYS PCB (utilizing the 6 sub-D pin connectors, typically J405, J408, etc.). Downstream, it terminates heavy field wiring: Generator Potential Transformers (PTs)​ for voltage feedback and Current Transformers (CTs)​ (1A/5A) for current feedback. It also hosts two heavy-duty Trip Relay outputs​ (Form-C) for driving customer lockout devices and seven auxiliary contact inputs​ wetted by an isolated 55V DC​ supply. Unlike TMR versions, this board has no voting logic; it is a straight 1:1 signal path for non-redundant exciters or auxiliary regulation loops.

Core Technical Specifications

• Operation Mode:​ Simplex​ (H3 Group Variation)
• Signal Inputs:​ 2x Gen CT (1A/5A), 2x Gen PT (3-Phase, Configurable)
• Auxiliary Inputs:​ 7x Contact Inputs​ (Wetted by 55V DC from J13M1)
• Relay Outputs:​ 2x Form-C Trip Relays​ (K1, K2), Rated for 125V DC Coil Drive
• General Relays:​ 4x Form-C (K1GP-K4GP) – Available on some sub-revs
• Processor I/F:​ 6x D-Sub Connectors​ (For HSLA/EMIO Daughter Cards)
• Power Interface:​ J13M1 (55V DC Input from M1 Power Supply)
• Signal Conditioning:​ Onboard Isolation Transformers (CT/PT Galvanic Isolation)
• Terminals:​ Screw-Type Barrier Strips (Accept #12 – #24 AWG)
• Indicators:​ Status LEDs​ per Input (Illuminates when contact wetted/closed)
• Mounting:​ Chassis Mount (Exciter Cabinet Frame)
• Environmental:​ -40°C to +85°C (Operational)

Customer Value & Operational Benefits

Simplex Cost Efficiency

The “H3” (Simplex) design is the primary value prop for single-unit applications (e.g., a standalone Hydro plant exciter). You avoid paying for the redundant hardware overhead of H1 (TMR) or H2 (Dual). This cuts CAPEX by 40-60%​ on the I/O termination side while retaining full signal conditioning (CT/PT isolation) and trip relay functionality.

Centralized Excitation I/O

Consolidates PT/CT termination, Trip Relays, and Aux Contacts​ onto one PCB. In retrofit jobs squeezing an EX2100e into an old GE EX2000 footprint, this density eliminates the need for separate “PT Boxes” and “Relay Panels,” reducing panel footprint by 30%​ and shortening field cable runs.

Isolation for Metering

The onboard Isolation Transformers​ for CT/PT inputs are critical. Excitation systems are noisy (thyristor switching). These transformers block ground loops and transient spikes from the generator stator, ensuring the AVR (Auto Voltage Regulator)​ sees a clean sine wave. This prevents VAR hunting or spurious “Over/Under Excitation” trips during grid disturbances.