Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | IS200TBTC1CBB |
| Manufacturer | GE Energy / GE Boards & Turbine Control |
| Product Type | Thermocouple Input Terminal Board (TBTC) |
| System Compatibility | GE Mark VI / Mark VIe IS200 |
| Thermocouple Types | E, J, K, S, T |
| Input Span | -8 mV to +45 mV |
| Number of Channels | Up to 24 (depends on pack/revision pairing) |
| Compatible I/O Packs | VTCC (IS200VTCCH1CBB), PTCC |
| Redundancy Mode | Simplex with TBTCH1C; TMR with TBTCH1B |
| Cold-Junction Compensation | Built-in on terminal board |
| Field Connection | Barrier/screw terminal blocks |
| Pack Interface | DC connector to VTCC/PTCC pack |
| Noise Suppression | High-frequency noise filtering |
| Operating Temp. | Approx. 0°C to +45°C (board-level) |
| Storage Temp. | -25°C to +70°C |
| Protection Rating | IP20 (control cabinet mounting) |
| Mounting | Rack/cabinet mounted via backplane or DIN hardware |
Product Introduction
The IS200TBTC1CBB is GE’s thermocouple input terminal board for the Mark VI and Mark VIe IS200 turbine control family. It is the field-facing side of the temperature measurement chain — the board where exhaust thermocouples, bearing temperature sensors, and process thermocouples actually land before being passed into the I/O pack for digitization and voting.It supports E, J, K, S, and T thermocouple types over a -8 mV to +45 mV span, with cold-junction compensation handled on the board itself. In a simplex configuration, the TBTCH1C variant typically supports up to 24 inputs through two barrier terminal blocks. In a TMR configuration, the TBTCH1B variant is used with three VTCC/PTCC packs, and the effective channel count per pack drops because the inputs are split across the redundant channels.One thing to watch: the TBTC is a terminal board, not the processor. The actual A/D conversion, linearization, and voting happen in the VTCC (IS200VTCCH1CBB) or PTCC pack that plugs into it. If you are replacing a failed TBTC, you must verify that the I/O pack revision matches the terminal board revision — swapping a TBTCH1B into a system configured for TBTCH1C will break the redundancy mapping.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
Every unit ships after:
- Visual and counterfeit check — housing, label revision (H1B vs. H1C), terminal block condition, DC connector pins.
- Continuity check — verify each thermocouple terminal maps correctly to the DC connector pins.
- Cold-junction sensor check — confirm CJ sensor resistance/response is within spec.
- Insulation check — verify no shorts between adjacent thermocouple channels.
- Connector seating test — confirm the DC connector mates cleanly with a VTCC/PTCC pack.
- Anti-static bag sealing with revision and lot logging.
The Engineer’s Warning (Pitfalls)
Two mistakes will cost you a turbine trip. First, confusing TBTCH1B with TBTCH1C. The “B” revision is for TMR; the “C” revision is for simplex. Drop the wrong one in, and your redundant temperature readings will be misaligned or incomplete. Second, losing the thermocouple wiring map. These boards carry dozens of small-gauge thermocouple wires. If you pull the board without photographing and labeling every terminal, re-terminating correctly is nearly impossible. I once watched a combined-cycle plant spend eight hours re-mapping exhaust thermocouples because a tech assumed the wire colors matched the drawing. They didn’t. Don’t be that tech.Also: verify the full order code. “IS200TBTC1CBB” and “IS200TBTCH1CBB” are closely related but may reflect different revision label conventions. Send a nameplate photo before ordering.
Installation & Configuration Guide
- Pre-Installation ⚠️
- Follow proper LOTO on the turbine control cabinet.
- Photograph every thermocouple wire position on the terminal blocks.
- Note the revision code (e.g., TBTCH1B, TBTCH1C) on the old board.
- Verify the paired I/O pack type (VTCC/PTCC) and revision.
- Removal
- Label every thermocouple wire by terminal position.
- Disconnect the DC connector from the I/O pack gently.
- Remove mounting hardware and extract the terminal board.
- Installation
- Verify the revision matches the old board. B and C revisions are not interchangeable in most configurations.
- Mount the new TBTC in the same position.
- Reconnect the DC connector to the I/O pack firmly.
- Re-terminate thermocouple wires per your labels and photographs.
- Verify cold-junction compensation hardware is intact.
- Power-On & Testing
- Restore power and verify the I/O pack boots without fault.
- Check thermocouple readings in ToolboxST against known reference values.
- In a TMR system, verify all three channels report consistent temperatures.
- Run the turbine through a controlled test cycle before releasing to service.
Compatible Replacement Models
| Replacement | Compatibility | Notes |
|---|---|---|
| IS200TBTC1CBB (same revision) | ✅ Drop-in | Exact match. Preferred for spare replacement. |
| IS200TBTCH1CBB | ⚠️ Revision dependent | Closely related TBTC variant. Verify H1B vs. H1C suffix and simplex/TMR configuration before swapping. |
| IS200TBTCH1B | ⚠️ TMR only | For triple modular redundant configurations with three VTCC/PTCC packs. Not a simplex replacement. |
| IS200TBTCH1C | ⚠️ Simplex only | For simplex configurations. Not a TMR replacement. |
| DTTC (DIN-style TBTC) | ❌ Hardware mod required | DIN-rail variant. Requires different mounting and wiring hardware. Not a direct swap. |
Frequently Asked Questions (FAQ)
Q: Can I hot-swap an IS200TBTC1CBB?
A: The TBTC is a passive terminal board — it has no processor or firmware. But pulling it while the I/O pack is live will open all thermocouple circuits, which will cause temperature faults and likely trip the turbine. Do not hot-swap. Plan a maintenance window.Q: What’s the difference between TBTCH1B and TBTCH1C?
A: TBTCH1B is used in TMR configurations with three I/O packs; TBTCH1C is used in simplex configurations. The channel mapping and redundancy behavior differ. They are not interchangeable without reconfiguring the I/O architecture.Q: How many thermocouples can this board handle?
A: Up to 24 in a simplex TBTCH1C configuration. In a TMR TBTCH1B configuration, the 24 inputs are distributed across three packs, so each pack sees fewer channels.Q: What I/O packs does this work with?
A: VTCC (IS200VTCCH1CBB) and PTCC packs. The pack handles A/D conversion and voting; the TBTC handles field termination and cold-junction compensation.Q: What warranty do you offer?
A: 12 months covering defects, spec mismatch, and testing oversights. Damage from ESD, incorrect wiring, or improper installation is not covered.Q: How do I verify authenticity before installing?
A: Check three things: the full order code and revision on the label, the terminal block condition and pin continuity, and successful thermocouple readings in ToolboxST after installation. If any of those fail, don’t put it in service.
