The IS200TREGH1BDC is a Turbine Emergency Trip (TREG) terminal board manufactured by GE Energy as part of the Mark VI™ and Mark VIe™ turbine control systems. This terminal board provides high‑integrity emergency trip functionality for gas and steam turbines. The TREG board supplies power to up to three emergency trip solenoids and is controlled by the I/O controller (VPRO in Mark VI systems or PPRO in Mark VIe systems). It works in conjunction with the TRPG terminal board, where TREG provides the positive side of the DC power to the solenoids and TRPG provides the negative side.
The IS200TREGH1BDC is based on the H1B variant, which is the primary version for 125 V dc applications. The suffix BDC indicates a specific factory configuration (e.g., special coating, component selection, or revision) that maintains full backward compatibility with all existing TREG applications. This board is used in simplex and redundant emergency trip systems, providing three independent trip channels with voting inputs to ensure that any single failure does not prevent a valid trip command.
The TREG board integrates with the turbine protection module to deliver emergency overspeed protection, emergency stop functions, and control of 12 relays. Nine of these relays are arranged in three groups of three to vote on inputs that control the three trip solenoids. The board also includes diagnostic features that monitor fuse integrity, cable connections, and relay status, as well as an on‑board ID device for hardware verification.
Functional Description
The IS200TREGH1BDC is a critical component of the turbine emergency trip system. Its primary functions are:
Power distribution to trip solenoids – Provides the positive side of 125 V dc power to up to three trip solenoids. The negative side is supplied by the TRPG terminal board.
Trip relay control – Contains nine emergency trip relays (ETR1, ETR2, ETR3) arranged in three groups of three. Each group controls one solenoid. Two series contacts from each group are connected in the positive feeder to the corresponding solenoid.
Economising relays – Includes three economiser relays (KE1, KE2, KE3) that have normally closed contacts in parallel with current‑limiting resistors. After the solenoids are energised, these relays reduce the holding current to minimise power dissipation.
Manual emergency stop – Accepts an external emergency stop contact (E‑STOP) that directly trips the master trip relays (K4X, K4Y, K4Z), removing the 28 V dc control power from the ETR and KE relay coils.
Servo clamp output – Provides a relay contact (K4CL) that signals the TSVO servo terminal board to clamp the servo valves closed upon a turbine trip (simplex systems only).
Trip interlock inputs – Accepts up to seven trip interlock signals from external protection devices (e.g., vibration, temperature, flame detectors) that are fed to the I/O controller.
Diagnostic monitoring – Monitors the 125 V dc feeder voltage, fuse integrity, relay driver feedback, and solenoid voltage. Generates alarms if any parameter deviates from expected values.
In Mark VI systems, the TREG interfaces with the VPRO protection module via cables with moulded plugs. In Mark VIe systems, it interfaces with the PPRO I/O pack through the SPRO board. The board is configured by jumpers (JPA1, JPB1) and all other configuration is performed via the ToolboxST software.
Hardware Characteristics
The IS200TREGH1BDC is a printed wiring board designed for mounting inside the turbine control cabinet. Its dimensions are approximately 17.8 cm wide by 33.0 cm high (7.0 in × 13.0 in). The board includes multiple terminal blocks for field wiring, D‑sub connectors for interfacing with the protection module, and jumper headers for configuration.
Connectors and Terminals
Connector / Terminal | Type | Description |
J2 | Power input connector | Accepts 125 V dc from the turbine control power distribution module to supply the trip solenoids. |
JX1, JY1, JZ1 | 3‑pin connectors (each) | Connect to the VPRO/PPRO protection module sections R8, S8, T8. Carry 28 V dc control power for the ETR and KE relays, and also provide status feedback. |
JH1 | Connector | Used for monitoring the 125 V dc feeder and other diagnostic signals. |
TB1 (first terminal block) | Screw terminals | For wiring the three trip solenoids, economising resistors, and the emergency stop contact. |
TB2 (second terminal block) | Screw terminals | For wiring up to seven trip interlock inputs. |
J1 | Connector | In simplex systems, carries the servo clamp relay signal to the TSVO board. |
Jumpers
The board includes two configuration jumpers:
Jumper | Function |
JPA1 | Selects either current input or voltage input for the trip interlock circuits. |
JPB1 | Selects whether the return line is connected to common (PCOM) or left open (OPEN). |
Additionally, a jumper must be placed across terminals 15 and 17 on TB2 if the second emergency stop input is not used.
LED Indicators
The document does not specify onboard LEDs for the TREG board. Diagnostic status is provided by the I/O controller (VPRO/PPRO) via software and by the ID device verification.
Redundancy and Special Variants
The IS200TREGH1BDC is based on the H1B design, which includes diode‑combined power from JX1, JY1, and JZ1 for the status feedback and economiser relay circuits. For applications requiring redundant TREG boards (e.g., two TREG boards operating together), GE offers specialised variants:
H3B – Feedback and economiser relay power provided only by JX1.
H4B – Feedback and economiser relay power provided only by JY1.
H5B – Feedback and economiser relay power provided only by JZ1.
In redundant TREG installations, it is typical to use one H3B and one H4B together. The IS200TREGH1BDC is a standard H1B variant and is not intended for redundant TREG configurations where strict power separation is required. For such systems, use the appropriate H3B/H4B/H5B boards.
Installation and Wiring
Handling Precautions
Static sensitivity – The board contains static‑sensitive components. Always wear a wrist grounding strap and handle at a grounded workstation.
De‑energise before handling – Turn off all power to the turbine control system and verify zero voltage before touching the board or any connected circuits.
Do not insert or remove with power applied – May cause equipment damage or personal injury.
Installation Steps
Mount the IS200TREGH1BDC in the designated slot in the turbine control cabinet.
Connect the 125 V dc power feeder to connector J2 from the power distribution module. This feeder supplies the trip solenoids.
Connect the three 28 V dc control cables from the VPRO/PPRO protection module sections (R8, S8, T8) to connectors JX1, JY1, and JZ1 respectively.
Wire the trip solenoids to the first terminal block (TB1) as shown in the wiring diagram. Connect the positive side to the TREG terminals and the negative side to the TRPG board.
Wire the economising resistors and the emergency stop contact to TB1.
Wire up to seven trip interlock inputs to the second terminal block (TB2). If the second emergency stop input is not used, install a jumper between terminals 15 and 17.
In simplex systems, connect the servo clamp relay output (J1) to the TSVO terminal board.
Set jumpers JPA1 and JPB1 according to the application requirements (current/voltage input and return grounding).
Apply power and verify that the I/O controller recognises the board ID and that no diagnostic alarms appear.
Diagnostics
The I/O controller (VPRO or PPRO) continuously monitors the following TREG functions:
Trip relay driver and contact feedback
Solenoid voltage presence and level
Economiser relay driver and contact feedback
K25A relay (on TTUR) driver and coil
Servo clamp relay driver and contact feedback (K4CL)
Solenoid voltage source integrity (fuse and cable connection)
If any monitored parameter disagrees with the expected value, a fault is generated and reported via the control system.
The board also includes an ID device on each of the JX1, JY1, JZ1 connectors. These read‑only chips contain the board serial number, type, revision, and plug location. During power‑up, the I/O controller reads these IDs; a mismatch triggers a hardware incompatibility fault.
Configuration
The IS200TREGH1BDC has no on‑board switches. Configuration is performed as follows:
Hardware jumpers – JPA1 (current/voltage input), JPB1 (return to common or open).
Software configuration – All other parameters (e.g., trip interlock thresholds, solenoid test scheduling) are set using the ToolboxST application on the VPRO/PPRO controller.
Note: If the second emergency stop input is not used, a jumper must be installed across terminals 15 and 17 of TB2.
When ordering the IS200TREGH1BDC, use the complete part number exactly as shown. The part number follows GE’s convention:
IS200 – Innovation Series, 200‑class.
TREG – Functional acronym: Turbine Emergency Trip.
H1 – Generation/version (125 V dc).
B – Base variant (H1B).
D – Modifier (e.g., coating, component selection).
C – Revision C.
Warranty and Order Placement
Warranty replacements (within warranty period): Contact GE Energy Post Sales Service (contact details omitted per request).
Spare parts or non‑warranty orders: Contact your nearest GE Sales or Service Office. Provide:
Complete part number: IS200TREGH1BDC
Turbine control system serial number
Material List (ML) number
Note: All digits and letters in the part number are significant. GE may substitute later compatible revisions, but backward compatibility is assured. When replacing a TREG board in a redundant system, ensure the correct variant (H3B, H4B, H5B) is used to maintain power separation.
