IS210TRESH2A - Small Steam Turbine Emergency Trip Terminal Board

SPECIFICATIONS:

Part Number: IS210TRESH2A
Manufacturer: General Electric
Series: Mark VIe
Number of Trip Solenoids: 3
Trip Relay Coils Supply Voltage: 28 V DC
Trip Solenoid Supply Voltage: 125 V DC
L/R Time Constant: 0.1 sec
Number of Trip Relay Coils: 9
Number of Trip Solenoids Supported: 3
Connector Interfaces: J1
Product Type: Small Steam Turbine Emergency Trip Terminal Board
Mounting Type: DIN-rail
Common Mode Voltage Range: �5 V
Dimensions: 17.8 cm (W) x 33.02 cm (L)
Operating Temperature: 0 to 60 �C
Repair Time: 3�7 days
Availability: In Stock
Country of Origin: United States
Manual: GEH-6421M

FUNCTIONAL DESCRIPTION:

IS210TRESH2A is a Small Steam Turbine Emergency Trip Terminal Board manufactured and designed by General Electric as part of the VIe Series used in GE Distributed Control Systems. TRESH2A is used for the emergency overspeed protection for small/medium-sized steam turbines. TRES controls the I/O controller and provides power to three emergency trip solenoids, which can be connected between the TRES and TRPS terminal boards. TRESH2A provides the positive side of the 125 V DC to the solenoid, and TRPS provides the negative side. The I/O controller provides emergency overspeed protection and emergency stop functions, and it controls the three relays on TRESH2A, which control the three trip solenoids.

• Provides emergency overspeed protection for small/medium steam turbines.
• Controlled by an I/O controller and powers three emergency trip solenoids.
• Offers both simplex and TMR (Triple Modular Redundant) configurations.
• Has seven dry contact inputs for trip interlocks and no economizing relays or emergency stop inputs.
• Includes a synch check relay driver (K25A) and servo clamp relay driver (K4CL).
• Trip solenoids are wired to the first I/O terminal block, and trip interlocks to the second.
• The I/O controller controls TRES, and in simplex systems, a trip signal provides a servo valve clamp function.
• Trip solenoids are supplied with 125 V dc (or 24 V dc) and draw up to 1 A.
• Application software initiates online and offline tests for trip solenoids.
• Diagnostics monitor various components of the TRES board and connected devices.
• Specifications include details on trip solenoids (125 V dc/24 V dc), solenoid response time (0.1 sec), relay outputs, trip inputs, and interlock excitation.

In the TRES, the seven dry contact inputs, excitation, and signal are monitored and fed to the I/O controller. The board includes the sync check relay driver, K25A, and associated monitoring, the same as on TREG, and the servo clamp relay driver, K4CL, and its associated monitoring. A second TRES board cannot be driven from the I/O controller through J4.

INSTALLATION:

The board interfaces directly with the turbine�s trip system through its I/O terminal blocks. The first I/O terminal block accommodates the three trip solenoids, which are responsible for actuating the turbine�s hydraulic trip mechanism during emergency or overspeed conditions. Proper installation requires careful attention to wiring polarity, terminal torque, and insulation to ensure reliable solenoid operation. The second I/O terminal block supports up to seven trip interlocks, which monitor critical turbine conditions such as overspeed signals, pressure limits, or valve positions, ensuring that trip commands are executed safely and only under predefined conditions. Clear labeling of all wiring connections and interlocks is recommended to simplify maintenance and troubleshooting.

Power and signal distribution are handled through specific connectors to ensure reliable operation. Connector J2 carries three separate power buses from the TRPS (Trip Power Supply) board, delivering the required 125 V DC to energize the trip solenoids. Connector JH1 provides the excitation voltage for the seven trip interlocks, completing the interface between the TRES board and the turbine protection system. During installation, all connectors, including J1, J2, and JH1, must be securely fastened and properly seated to prevent intermittent connections. It is also important to verify grounding and shielding to minimize electrical noise.

OPERATION:

The VSVO protection module plays a critical role in turbine safety by controlling the TRES (Trip Emergency System). In simplex systems, an additional third cable is employed to transmit a trip signal from connector J1 directly to the TSVO terminal board. This signal activates the servo valve clamp function, which serves as a vital protective mechanism by quickly clamping the servo valve upon a turbine trip event, ensuring rapid shutdown and minimizing potential damage.

The TRES system, in coordination with TREL, governs the operation of trip solenoids #1 and #2, which are designed with built-in redundancy. This means that either solenoid can independently remove electrical power, triggering the hydraulic system to initiate valve closure, effectively stopping the flow of steam or fuel to the turbine. This redundancy is essential for maintaining high reliability and safety in turbine trip operations.

ETR3, another critical component, is configured to provide dedicated power to trip solenoid #3, further enhancing system redundancy and enabling fail-safe operation in case of failure in the primary trip solenoids. The trip solenoids themselves operate at a higher voltage level, receiving 125 V DC (in some configurations, 24 V DC) through plug J2. They are designed for robust performance, capable of drawing up to 1 Ampere of current and characterized by a 0.1-second L/R (inductance-to-resistance) time constant, allowing for rapid actuation and minimal delay in emergency shutdown scenarios.

• Servo Valve Clamping: This feature immediately halts servo valve motion during a trip, preventing unintended valve drift or overshoot that could compromise system safety.

• Fail-Safe Design: The use of multiple trip paths and solenoids (TREL, TRES, and ETR3) ensures the turbine can be safely shut down even if one or more components fail.

• Monitoring and Diagnostics: Advanced diagnostic functions in the protection module continuously monitor coil integrity, voltage supply, and solenoid response, enabling predictive maintenance and faster troubleshooting.

• Interface with Turbine Control System: The TRES and TREL modules integrate seamlessly with the turbine�s digital control system (e.g., Mark VIe or similar platforms), allowing real-time monitoring, remote trip command initiation, and event logging.

DIAGNOSTICS:

The I/O controller runs diagnostics on the TRES board and connected devices. The diagnostics cover the trip relay driver and contact feedback, solenoid voltage, K25A relay driver and coil, servo clamp relay driver and contact feedback, and the solenoid voltage source. If any of these do not agree with the desired value, a fault is created. TRES connectors JA1, JX1, JY1, and JZ1 have their ID device that is interrogated by the I/O controller. The ID device is a read-only chip coded with the terminal board serial number, board type, revision number, and plug location. When the chip is read by the I/O controller and a mismatch is encountered, a hardware incompatibility fault is created.

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FREQUENTLY ASKED QUESTIONS:

What is the primary function of the Emergency Trip Terminal Board in a steam turbine system?

The Emergency Trip Terminal Board serves as a critical interface between the turbine protection system and the trip solenoids. It receives trip signals�manual or automatic�from controllers and relays them to actuate trip solenoids.

How many trip solenoids can the terminal board support, and how is redundancy handled?

The board typically supports up to three trip solenoids. Solenoids #1 and #2 are controlled via the TREL and TRES modules, while Solenoid #3 is powered by the ETR3 channel for additional redundancy. The design allows any single solenoid to independently initiate a trip.

What are the voltage and current specifications for the trip solenoids?

Trip solenoids are powered with 125 V DC in most systems, though 24 V DC variants are also supported based on design requirements. Each solenoid draws up to 1 Ampere of current during activation. The solenoids exhibit a 0.1-second L/R time constant, which ensures fast electromagnetic operation for rapid valve actuation and safe turbine shutdown.