IS220PTCCH1A Thermocouple Input Module, Factory-Sealed

Supplied as new surplus in factory packaging, this IS220PTCCH1A is GE's Mark VIe thermocouple input pack in unused condition. It is the module a Mark VIe system uses to bring thermocouple temperatures — exhaust spread, wheelspace, bearings, and more — into the controller, and a factory-sealed example is a strong candidate for a critical spare.

The IS220PTCCH1A is a distributed I/O pack: a shared Mark VIe processor board joined to a thermocouple-specific acquisition board, mounted on a terminal board instead of a card rack. It communicates over the IONet through two RJ45 ports, takes power on a three-pin connector, and passes signals through a 37-pin connector to the terminal board.

Twelve Channels, One Terminal Board: How the PTCC Is Wired

Channel capacity is where the terminal-board pairing becomes concrete. A single IS220PTCCH1A reads up to 12 thermocouples. On a thermocouple terminal board in the TBTC family, a second pack raises the total to 24 inputs; in a triple-modular-redundant (TMR) arrangement, three packs — one each for the <R>, <S>, and <T> controllers — work through three cold junctions while the controller still sees 12 thermocouples. The acquisition board digitizes the millivolt signals with a 16-bit converter over a span on the order of -8 to +45 mV, and the reported thermocouple types cover E, J, K, and S (with T listed by some sources). Cold-junction compensation is handled at the terminal board, which is why the terminal board type and revision are part of any replacement decision.

Troubleshooting a Suspect Thermocouple Channel

Before treating a bad reading as a dead pack, remember that most thermocouple faults are in the field, not the electronics:

• Sensor: aged or open thermocouples are the usual culprit — verify against an adjacent point.
• Cold junction: a gradient or fault at the reference junction on the terminal board biases readings, often across many channels at once.
• Extension wire: confirm the correct type and polarity end to end.
• Terminal board, power, network: inspect the TBTC terminations and board, the three-pin power feed, and the IONet path.

Let the status LEDs and ToolboxST diagnostics confirm the fault location before you unseal a spare.

Reading the Part Number and Suffix

The number breaks into IS220 (Mark VIe distributed I/O pack), PTCC (thermocouple input function), and H1A (group and revision). The final letter advances with hardware revisions; match both the suffix and the label revision to the unit you are replacing. Full detail is in our GE Speedtronic Part Number Decoder.

Related Mark VIe Boards and Guides

The PTCC pairs with the RTD-oriented PRTD pack to cover turbine temperature sensing. For the move from the earlier control generation to IS200/IS220, read Mark V vs Mark VI: DS200 to IS200. Wider inventory is under GE Mark VI IS200 Boards and GE Speedtronic Turbine Control Boards.

Assembling Your Quote Request

• Full part number and suffix (IS220PTCCH1A) plus the label revision.
• A label photo, and the TBTC terminal board type if known.
• Turbine model and Mark VIe generation.
• Quantity and urgency.

Request a Quote for the IS220PTCCH1A

This IS220PTCCH1A is new-surplus, factory-packaged stock, backed by the warranty stated below. Press Request a Quote for a response within 24 hours. We ship worldwide on DDP terms and accept purchase orders.