How the TSVC Terminal Board Closes the Valve Position Loop

Every servo-positioned valve on a Speedtronic-controlled turbine depends on one round trip: drive current out to the servo valve coil, position feedback back from the LVDTs. The IS200TSVCH1A Servo Input/Output (TSVC) terminal board is where both halves of that round trip meet the field wiring. GE's documentation describes two servo channels serving two electro-hydraulic servo valves that actuate steam or fuel valves, with each servo regulator loop able to use one, two, three, or four LVDTs — up to eight LVDT winding inputs in total, excited from this board.

Coil drive is configurable: documented output options cover servo coils rated 10, 20, 40, 80, or 120 mA, selected by jumpers on the board, and in a TMR system each of the two servo outputs can drive up to three coils so that all three control sections hold authority over the valve. Two pulse-rate inputs (magnetic or TTL pickups) are provided for gas turbine fuel flow measurement. Everything terminates on two removable 24-point barrier terminal blocks accepting up to #12 AWG wire, and the board runs in simplex, dual, or TMR system architectures.

Five Checks Before You Swap a Servo Terminal Board

The intelligence of this loop lives in the servo I/O electronics; the TSVC mostly terminates, excites, and routes. That is why a methodical check usually finds the fault elsewhere:

• 1. Read the actual diagnostic. The documented diagnostics — servo current excessive or not responding, LVDT feedback out of range — are generated by the mating servo electronics and can be examined in detail from the configuration tool. Start from the specific diagnostic text, not from the assumption that the board failed.
• 2. Exploit the dual-sensor logic. Where a regulator uses two LVDTs, documentation notes the bad sensor is dropped from the feedback calculation while the good one carries the loop. If the loop still runs on one sensor, you are more likely dealing with a transducer or wiring fault than a board fault.
• 3. Test the field side at the terminal block. Coil resistance and LVDT continuity measured right at the block isolate the field run. Excitation present at the block but missing at the LVDT points to cable, not board.
• 4. Check jumper positions after any prior swap. Coil current on this board is jumper-selected per coil. A replacement board left on default jumpers will misbehave in ways that look like a servo failure.
• 5. Separate trips from faults. The external trip plugs (JD1/JD2) and the board's protection-driven relay mean a valve can be forced to its safe state by design. Confirm the protection side was quiet before blaming hardware.

Part Number Anatomy: IS200TSVCH1AAA

IS200TSVCH1AAA parses as IS200 (board series) + TSVC (servo input/output terminal board) + H1 (hardware group) + A (functional revision), with the final letter pair AA marking the manufacturing revision on the label. The base number IS200TSVCH1A defines form, fit, and function; the trailing pair tracks build level. If your plant's spare matches the base number but shows different trailing letters, include both strings in your request and we will verify interchangeability. The complete numbering logic — prefixes, acronyms, groups, and revisions — is laid out in our GE Speedtronic Part Number Decoder.

Related Speedtronic Servo Hardware

Documentation for this family draws a hard line: TSVC works with the PSVO servo I/O pack and WSVO servo driver, and does not pair with the VSVO processor card — VSVO-based racks take the separate TSVO terminal board. Since both boards do servo termination, verifying the silk-screened acronym on your existing board is the single most valuable pre-order step. TSVC sits within the broader IS200 I/O ecosystem alongside terminal boards for thermocouples, analog I/O, and contact inputs; you can see the whole platform in our GE Mark VI IS200 Boards collection, or step back to the full GE Speedtronic Turbine Control Boards range if your site runs mixed generations.

Quoting IS200TSVCH1AAA: What We Need from You

• Complete part number with revision suffix (IS200TSVCH1AAA here), ideally with a photo of the label
• Your turbine model and whether the loop is simplex, dual, or TMR
• The servo electronics part number the board cables to, if you have it
• Quantity, target condition (used tested vs new surplus), and delivery urgency

Get Your 24-Hour Quote

This IS200TSVCH1AAA is supplied used, cleaned and tested, with the warranty listed in the table below. Hit Request a Quote and we will come back to you within 24 hours with availability and lead time — shipped worldwide on DDP terms, purchase orders welcome.

General Information about the Product
Part Number	IS200TSVCH1A Mark VI IS200
Description	IS200TSVCH1A By General Electric IS200TSVCH1AAA Servo Terminal Board
Condition	used Cleaned and Tested. With 1 Year Warranty.