The IS200TDBTH2A is a Discrete Input/Output (TDBT) terminal board from GE's Speedtronic IS200 catalog — the hardware family that carries field wiring for Mark VI and Mark VIe turbine control installations. It is the physical landing point where plant discrete signals such as pressure switches, limit switches, starter feedback contacts, and solenoid commands meet the control system. The unit on this page is supplied as new surplus in factory packaging, with the condition and warranty spelled out in the table at the bottom.

What the IS200TDBTH2A Does in a Speedtronic Cabinet

GE's system documentation (manual reference GEH-6721) describes TDBT as a flat or DIN-rail mounted TMR contact input/output terminal board. It provides 24 group-isolated contact inputs that run on a nominal 24, 48, or 125 V dc wetting voltage supplied from an external source, with onboard noise suppression against surge and high-frequency interference, plus 12 form-C relay outputs for switching commands back to the plant. Published excerpts specific to the TDBTH2 version note that its associated 24 V dc supply is current-limited to 0.5 A through resettable polymer PTC fuses.

On the system side, the board is served by PDIO Discrete I/O packs that mount on its D-type connectors — three positions, JR1, JS1, and JT1 — and communicate with the controllers over Ethernet. GE is explicit that TDBT is not designed to operate correctly with a single PDIO pack; the board exists for redundant arrangements. Field conductors, typically #18 AWG, land on two banks of screw terminals: the upper block (TB1) serves the relay section, the lower block (TB2) the contact inputs. The terminal board itself carries no configuration jumpers; channel setup lives in the I/O pack configuration.

Before You Replace It: Prove the Fault Is Actually the Board

Terminal boards are mostly passive interconnect plus relays, so start with the items that fail far more often:

• One contact input reads dead. Confirm the field contact actually closes and that wetting voltage is present across the terminal pair. A failed field device, a broken conductor, or a lost wetting supply mimics a bad input channel exactly.
• Every input dead at once. That is a wetting-supply or I/O pack problem, not 24 simultaneous channel failures on one board.
• Alarms from a single redundant channel only. Reseat or exchange the PDIO pack on the affected connector. A fault that follows the pack clears the board; a fault that stays on the position points to the board or its wiring.
• A relay output that never changes state. The 12 form-C relays do live on the TDBT itself, so a welded or burned contact is a genuine board failure — but first verify the output command is being issued, and inspect the load circuit for the short that may have caused the damage.
• Loose lugs and corroded screws. Intermittent discrete signals trace to terminal hardware more often than to board electronics.

Reading the IS200TDBTH2A Part Number

Break the number into IS200 (the Speedtronic board series associated with GE's Salem, Virginia operation), TDBT (the functional acronym for this Discrete Input/Output terminal board), and H2A (the hardware group and version). Labels frequently append two more revision letters — elsewhere in this family you will see strings like IS200TDBTH6AAA, which is base number IS200TDBTH6A at the AA revision. Within the TDBT family the group number (H2, H4, H6, H8) selects the hardware build, so replace like for like rather than assuming the groups interchange. Our GE Speedtronic Part Number Decoder walks through the numbering logic in detail.

Boards and Packs That Work Alongside TDBT

The system guide notes that TDBT's input conditioning matches the STCI contact-input terminal board and that its relay terminal assignments follow the SRLY relay board — useful when cross-referencing point lists. An optional WROB relay card can plug onto connectors JW1 and JW2 to extend relay functionality; the WROBH1 version carries six jumpers that configure individual relays for dry contacts or power distribution. The mating service hardware is the PDIO Discrete I/O pack. Browse neighboring hardware in our GE Mark VI IS200 Boards collection or the full lineup under GE Speedtronic Turbine Control Boards; if your site also runs earlier-generation panels, the guide Mark V vs Mark VI: DS200 to IS200 explains how the board numbering evolved between platforms.

What to Send Us for an Exact-Match Quote

• The complete part number from the board label, including trailing revision letters
• A photo of the label — it settles revision and hardware-group questions instantly
• Turbine model and control platform (Mark VI or Mark VIe), plus the I/O pack type installed
• Whether the position uses a WROB relay option card, and its number if so
• Quantity, and whether this is a forced outage, a planned outage, or a shelf spare

Request a Quote for the IS200TDBTH2A

Send a Request a Quote with the details above and our team will come back within 24 hours. We ship worldwide on DDP terms — customs and import charges handled before delivery — and we accept purchase orders from industrial buyers. Condition and warranty for this specific unit are stated in the table below.

General Information about the Product
Part Number	IS200TDBTH2A Mark VI IS200
Description	IS200TDBTH2A By General Electric Discrete Terminal Board Mark VI NSFP
Condition	newSurplusFactoryPackage Cleaned and Tested. With 1 Year Warranty.