The DS200TCRAG1A is a Relay Output Board designed by General Electric (GE) Industrial Systems for its Mark V LM turbine control system. Belonging to the TCRA (Relay Output Board) series, this board is part of the G1 group and represents revision A. It is installed in the fourth and fifth positions of the digital I/O cores (<Q11>, <Q21>, and <Q51>), serving as a core component for discrete output control within the Mark V LM control system.
The primary function of the TCRA relay output board is to convert control signals from the control system (TCDA board or TCQE board) into relay contact outputs to drive field devices such as solenoid valves, contactors, indicator lights, and alarms. The board utilizes plug-in electromagnetic relays with Form C (1NO+1NC+COM) contact configurations, supporting loads at various voltage levels, including 125 V dc, 28 V dc, 120 V ac, and 240 V ac. Through hardware jumpers on the termination boards, certain outputs can be configured as “wet” contacts (internally powered by the Mark V LM) or “dry” contacts (externally powered) to accommodate different application requirements.
The DS200TCRAG1A board embodies GE’s commitment to reliability and flexibility in turbine control and features the following characteristics:
High-Density Relay Output: Supports up to 30 relay outputs per board.
Flexible Configuration Options: Outputs can be configured as solenoid outputs or dry contact outputs via hardware jumpers on the DTBC/DTBD termination boards.
Multiple Load Support: Suitable for various voltage levels including 125 V dc, 28 V dc, 120 V ac, and 240 V ac.
Modular Design: Works in conjunction with the TCDA board and termination boards to form a complete digital output system.
Reliable Electromagnetic Relays: Utilizes plug-in electromagnetic relays with long contact life and high reliability.
Special Output Support: Certain outputs support 120/240 V ac high-current loads, suitable for ignition transformers and similar applications.
This product is widely used in gas turbine control systems, steam turbine control systems, generator protection systems, and various industrial process control applications, particularly in turbine control applications requiring extensive discrete output control.
II. Key Functions
1. Relay Output Control
The core function of the DS200TCRAG1A board is to convert control signals from the TCDA board (digital I/O core) or the TCQE board (LM6000 I/O Processor) into relay contact outputs. Each relay output is a Form C type, providing normally open (NO), normally closed (NC), and common (COM) three-wire contact combinations. Relay outputs can drive various field devices, including solenoid valves, contactors, indicator lights, and alarms.
2. Multiple Relay Configurations
The DS200TCRAG1A board offers different relay quantity configurations depending on the installation location:
| Core | Installation Location | Number of Relays | Remarks |
| <Q11>, <Q21>, <Q51> | Fourth position | 30 | Standard configuration |
| <Q11> | Fourth position | 4 | Special configuration for gas manifold blow-off valve control |
| <Q11>, <Q21>, <Q51> | Fifth position | 30 | Standard configuration |
3. Solenoid Output Configuration
Through hardware jumpers on the DTBC and DTBD termination boards, certain relay outputs can be configured as solenoid outputs (internally powered by the Mark V LM) or dry contact outputs (externally powered):
Solenoid Output: Internally powered by the Mark V LM controller (125 V dc or 120/240 V ac), directly driving the load.
Dry Contact Output: Provides only relay contacts; power is supplied by external equipment.
Specific configuration capabilities are as follows:
| Core | Position | Number of Outputs Configurable as Solenoids |
| <Q51> | Fourth position | 18 outputs (out of 30) |
| <Q11>, <Q51> | Fifth position | 16 outputs (out of 30) |
4. High-Current Output Support
The DS200TCRAG1A board provides two additional contact outputs (#47 and #48) in the fifth position (for <Q11> and <Q51> cores). These outputs receive 120/240 V ac power via J19 and J20 connectors and can directly drive high-current loads such as ignition transformers. These outputs are factory-configured with jumpers and require no additional setup.
5. Interface with TCDA Board
The DS200TCRAG1A board connects to the TCDA board via JS1-JS8 connectors. Each JS connector corresponds to 4 relay outputs, with 8 connectors covering 30 relay outputs. In the fourth position of the <Q11> core, the TCRA board receives control signals from the TCQE board via the JO connector for gas manifold blow-off valve control.
6. Interface with Termination Boards
The DS200TCRAG1A board outputs relay contacts to the DTBC or DTBD termination boards via JS1-JS8 connectors. The termination boards provide field wiring terminals, and hardware jumpers on these boards determine whether outputs are configured as solenoid outputs or dry contact outputs.
III. Hardware Architecture
1. Board Structure
The DS200TCRAG1A board uses a standard printed circuit board structure and is installed in the board carrier of the digital I/O cores. The board includes:
Up to 30 plug-in electromagnetic relays (K1-K30)
JS1-JS8 Connectors: For interfacing with the TCDA board or termination boards
JO Connector: For receiving control signals from the TCQE board (only fourth position of <Q11> core)
JOR, JOS, JOT Connectors: Typically not used
2. Relay Specifications
The relays on the DS200TCRAG1A board are plug-in electromagnetic relays with the following contact specifications:
| Voltage Type | Voltage Level | Current Rating | Remarks |
| AC | 120 V ac | 2 A inductive/3 A resistive | 10 A inrush |
| AC | 220-240 V ac | 2 A inductive/3 A resistive | 10 A inrush |
| DC | 125 V dc | 0.2 A (without suppression)/0.5 A (with suppression) | — |
| DC | 28 V dc | 2 A inductive/3 A resistive | — |
3. Connector Description
| Connector | Type | Function Description |
| JS1-JS8 | Plug-in | Interface with TCDA board or DTBC/DTBD termination boards; each connector corresponds to 4 relays |
| JO | Plug-in | Receives control signals from TCQE board (only fourth position of <Q11> core) |
| JOR, JOS, JOT | Plug-in | Typically not used |
4. Power Configuration
The DS200TCRAG1A board itself does not contain power circuits. The power for the relay coils is supplied by the TCDA board or TCQE board. Contact-side power is sourced from the <PD> core or external power supplies via the termination boards (DTBC/DTBD).
IV. Detailed Interface Description
1. JS1-JS8 Connectors
The JS1-JS8 connectors are the interface between the TCRA board and the TCDA board or termination boards. Each connector corresponds to 4 relay outputs:
| Connector | Corresponding Relays | Output Numbers |
| JS1 | K1-K4 | 1-4 |
| JS2 | K5-K8 | 5-8 |
| JS3 | K9-K12 | 9-12 |
| JS4 | K13-K16 | 13-16 |
| JS5 | K17-K20 | 17-20 |
| JS6 | K21-K24 | 21-24 |
| JS7 | K25-K28 | 25-28 |
| JS8 | K29-K30 | 29-30 |
2. JO Connector
The JO connector is used to receive control signals from the TCQE board and is used only in the fourth position of the <Q11> core. This connector transmits control signals from the TCQE board to the TCRA board for special applications such as gas manifold blow-off valve control.
3. JOR, JOS, JOT Connectors
These connectors are typically not used on the TCRA board and are reserved for future functional expansion.
V. Configuration and Settings
1. Solenoid Output Configuration
Output configuration for the DS200TCRAG1A board is achieved through hardware jumpers on the DTBC and DTBD termination boards, not on the TCRA board itself. Configuration methods are as follows:
| Configuration Type | Jumper Setting | Description |
| Solenoid Output | Pn and Mn both IN | Internally powered by Mark V LM |
| Dry Contact Output | Pn and Mn both OUT | Externally powered; contacts only |
Note: In the <Q11> core, the TCRA board in the fourth position has only 4 relays used for gas manifold blow-off valve control. Its configuration differs from the standard configuration; refer to system drawings for details.
2. High-Current Output Configuration (#47, #48)
Configuration of outputs #47 and #48 involves connecting J19 and J20 connectors:
| Application | Configuration |
| Ignition Transformer | J19 and J20 connected to J19 and J20 of the <PD> core, receiving 120/240 V ac power |
| Other Applications | J19 and J20 not used; outputs #47-#48 used as dry contacts |
3. Software Configuration
Outputs on the TCRA board are controlled by the TCDA board or TCQE board through the Control Sequence Program (CSP). Software configuration includes:
Output Enable: Sets whether the output is used via the I/O Configurator.
Output Logic: Configurable output signal logic levels.
Failsafe Configuration: Sets output state during communication failure.
VI. Installation and Maintenance
1. Mounting Location
The DS200TCRAG1A board is installed in the fourth and fifth positions of the digital I/O cores (<Q11>, <Q21>, <Q51>). In the fourth position of the <Q11> core, the TCRA board is equipped with only 4 relays for gas manifold blow-off valve control.
2. Installation Steps
Verify Power is Off: Turn off power to the drive, wait several minutes for power supply capacitors to discharge, and test to verify that no power exists.
Open Cabinet Door: Access the printed wiring board area.
Locate the Slot: Confirm the fourth or fifth slot of the digital I/O core is available.
Insert the Board: Align the TCRA board with the slot guides and push it in smoothly until the backplane connectors are fully engaged.
Secure the Front Panel: Tighten the captive screws on the front panel to secure the board.
Connect Cables:
Connect JS1-JS8 ribbon cables to the TCDA board or termination boards.
If in the fourth position of the <Q11> core, connect the JO cable to the TCQE board.
Power On and Verify: After powering on, verify via the operator interface that the module is correctly recognized and communicating.
3. Removal Steps
Verify Power is Off: Ensure the system has been de-energized and verify that no power is present.
Disconnect Cables: Carefully disconnect all connectors (JS1-JS8, JO, etc.).
Loosen Front Panel: Loosen the captive screws on the front panel.
Remove the Board: Gently pull out the TCRA board.
4. Maintenance Recommendations
Periodic Inspection: Regularly check that relays are securely seated in sockets and that contacts are operating properly.
Anti-Static Precautions: Always wear a grounding strap when handling boards. Store boards in anti-static bags.
Contact Cleaning: If contact issues are found, consider replacing the relay (relays are plug-in and can be replaced individually).
Spare Parts Management: It is recommended to keep at least one identical TCRA board on-site as a spare to minimize downtime.
VII. Applications
The DS200TCRAG1A Relay Output Board is widely used in the following industrial scenarios:
Gas Turbine Control Systems: Controlling fuel shutoff valves, blow-off valves, ignition transformers, start motors, and other equipment.
Steam Turbine Control Systems: Controlling steam turbine inlet valves, extraction valves, drain valves, etc.
Generator Protection Systems: Controlling generator breakers, field breakers, alarm devices, etc.
Gas Manifold Blow-Off Valve Control: In the fourth position of the <Q11> core, controlling gas manifold blow-off valves for LP shaft shear protection.
Alarm and Indication Systems: Driving field alarm lights, buzzers, indicator lights, etc.
Auxiliary Equipment Control Systems: Controlling boiler feed pumps, fans, cooling water pumps, and other auxiliary equipment.
System Upgrade and Retrofit Projects: Replacing relay output modules in older systems with standardized interfaces and higher reliability.
