Servo Valve Termination on the Mark VI and Mark VIe Platform

When a servo regulator loop is down, the part you need is often the simplest one in the chain: the board where the valve wiring actually lands. The IS200TSVCH1A is that board — GE's TSVC Servo Input/Output terminal board from the Speedtronic IS200 hardware line. It terminates the field wiring for two electro-hydraulic servo valves that position the turbine's steam or fuel valves, provides excitation for the LVDTs that report valve position, and passes both signal directions on to the servo I/O electronics that close the loop.

According to published documentation, the board handles up to eight LVDT winding inputs with a choice of one to four LVDTs per servo control loop, two bidirectional servo current output channels, and two pulse-rate inputs (magnetic or TTL) used for fuel flow measurement on gas turbines; the pulse-rate signals can also participate in logic that shuts off the servo outputs. Wiring terminates on two pluggable barrier-type terminal blocks, 24 points each, rated for up to #12 AWG and each secured by two screws, with a chassis-grounded shield strip alongside. The board measures 33.02 cm by 17.8 cm, is built with surface-mount technology, and is specified for operation from -30 to 65 °C. Simplex, dual, and TMR architectures are all supported.

Is It Really the Terminal Board? A Pre-Order Checklist

Because the TSVC is largely passive interface hardware, most "servo board" symptoms trace back to something else. Run these checks first:

• Confirm where the diagnostic is generated. Servo diagnostics — output current not responding, LVDT feedback out of range — are performed by the mating servo I/O electronics, which then flag the alarm. A diagnostic alarm names the loop, not necessarily the failed component.
• Check the LVDT before the board. An out-of-range position signal usually means the transducer, its core linkage, or the field cable. Excitation for the LVDTs comes from this terminal board, so verifying excitation at the terminal block quickly splits the problem: excitation present but no signal points to the sensor side.
• Verify coil circuits at the block. With field wiring lifted, servo coil resistance measured at the terminal block tests the whole field run without pulling the board.
• Rule out a commanded shutdown. External trip connections (JD1/JD2) tie this board to the protection side of the system; a servo output forced safe during a trip is expected behavior.
• Look at what is shared. If both servo channels and all LVDT inputs fail together, suspect the 28 V dc supply through J28, the cabling to the I/O electronics, or the electronics themselves before the terminal board.

IS200TSVCH1AJE: Group, Revision, and the JE Suffix

Break the number apart and it reads: IS200 series, TSVC function (servo input/output termination), hardware group H1, functional revision A. The final letter pair on the label — JE here — records the manufacturing revision of the board as built. Sites with strict revision control should order against the full string; if your label shows a different trailing pair on the same IS200TSVCH1A base, send it with your request and we will confirm the match. Our GE Speedtronic Part Number Decoder covers the whole numbering system, including how IS200 boards differ from the older DS200 line.

Where TSVC Sits Relative to PSVO, WSVO, and VSVO

Compatibility is the trap with this family. The TSVC is documented as working with the PSVO servo I/O pack and the WSVO servo driver — and as not compatible with the VSVO processor card. Racks built around VSVO use the separate TSVO terminal board instead, and the two look similar at a glance. Before you order, read the acronym printed on the board you are replacing and note which servo electronics cable into it. Our article Mark V vs Mark VI: DS200 to IS200 gives the background on how these hardware generations fit together.

Details That Speed Up Your Quote

• The complete part number from the label — IS200TSVCH1AJE for this unit — plus a label photo if you can get one
• Which servo electronics the board mates with in your system (PSVO pack or WSVO driver part number)
• Turbine frame and fuel type, and whether the system is simplex, dual, or TMR
• Quantity needed and whether this is a planned outage buy or an emergency

New Surplus IS200TSVCH1AJE in Factory Packaging

This listing is a new surplus IS200TSVCH1AJE in its factory package, with the warranty shown in the table below. Use the Request a Quote button and you will hear back from us within 24 hours. We deliver worldwide DDP — duties and customs handled — and we accept purchase orders. For adjacent spares on the same platform, see the GE Mark VI IS200 Boards collection.

General Information about the Product
Part Number	IS200TSVCH1A Mark VI IS200
Description	IS200TSVCH1A By GE IS200TSVCH1AJE Servo I/O PCB New Surplus Factory Package
Condition	newSurplusFactoryPackage With 1 Year Warranty.