IS200TSVCH1A - SERVO TERMINAL BOARD

IS200TSVCH1A is a Servo I/O Terminal Board developed by GE. Two electro-hydraulic servo valves actuate the steam/fuel valves, and the Servo Input/Output (TSVC) terminal board interacts with them. Linear variable differential transformers are used to measure valve position (LVDT). TSVC is only compatible with the PSVO I/O pack and the WSVO servo driver; it is not compatible with the VSVO processor. Simplex, dual, and TMR control are all supported by the terminal board. Through socket J28, three 28 V dc supply are connected. JD1 or JD2 is external trip plugs for the protection module.

IS200TSVCH1A Installation

Two I/O terminal blocks are used to connect sensors and servo valves. Each block has 24 terminals that accommodate up to #12 AWG wiring and is held in place by two screws. To the left of each terminal block is a shield terminal strip that is connected to chassis ground. JD1 or JD2 are used to connect external trip wiring.

Operation

Two channels of bi-directional servo current outputs, LVDT position feedback, LVDT excitation, and pulse rate flowing inputs are available on the TSVC servo terminal board. It can excite up to eight LVDT valve position inputs and accept data from them. For each servo control loop, one, two, three, or four LVDTs are available. For gas turbine fuel flow monitoring, the two pulse rate inputs are employed.

There is a choice of one, two, three, or four LVDTs for each servo control loop. The two pulse rate inputs are used for gas turbine fuel flow measurement.

Number of inputs

• There are eight LVDT windings in total.
• Two pulse rate signals, magnetic or TTL
• To turn off servo outputs, two pulse rate signals, magnetic or TTL, are used.

Number of outputs

• 10, 20, 40, 80, 120 mA servo valves with three coils each
• LVDTs have four different sources of excitation (transformer isolation)
• LVDTs have two different sources of excitation (no transformer isolation), Pulse rate transducers require two 24 V dc excitation sources.

Diagnostics

PSVO performs the following diagnostic checks on the terminal board components:

• The output servo current is excessive or not responding, causing a fault.
• The signal from the regulator feedback (LVDT) is out of range, causing a problem.
• If the related regulator has two sensors, the poor sensor is eliminated from the feedback calculation and the good sensor is used.
• If any of the above signals becomes unhealthy, L#DIAG PSVO is triggered.
• The ToolboxST program provides details about the individual diagnostics. Individual diagnostic signals can be latched and reset using the RESET DIA signal if they become healthy.

IS200TSVCH1A Configuration

In a simplex system, jumper JP1 is used to set the proper coil current for servo 1, while jumper JP4 is used to set the correct coil current for servo 2. Each servo output in a TMR system can have three coils. In this scenario, JP 1-3 for servo 1 and JP 4-6 for servo 2 are used to jumper select each coil current. The ToolboxST application is used to configure all other servo boards.