An Open-Box IS220PRTDH1A RTD Input Pack for Mark VIe

Listed here as an open-box, new-surplus IS220PRTDH1A, this is a GE Mark VIe RTD input pack that has left its original packaging but has not been placed in service. Functionally it is the same Resistance Temperature Device (RTD) input pack that a running Mark VIe system relies on to turn RTD resistance into the temperature values the controller acts on. For a spare that will sit on the shelf until a temperature channel misbehaves, an unused open-box pack is often the practical middle ground.

In the cabinet the pack snaps onto an RTD terminal board in the TRTD family, mating through a 37-pin connector, drawing power from a three-pin input, and exchanging data with the controller over two RJ45 IONet ports. A single IS220PRTDH1A reads up to eight three-wire RTDs, exciting each with a multiplexed 10 mA DC current and digitizing the result several times a second. Because the pack shares one acquisition path across its channels, its behavior is consistent from channel to channel — a useful fact when you are trying to tell a pack fault from a field fault.

Is the Pack Actually the Problem? A Pre-Purchase Checklist

Before you commit to a replacement pack, spend a few minutes confirming that the pack is what failed. On RTD inputs, a bad temperature reading points at the sensor and its wiring far more often than at the electronics:

• Isolate the channel. If one input is wrong while the rest are fine, the odds favor that RTD, its terminal, or its cable run — not the pack that reads all eight.
• Check lead resistance and distance. Keep the two-way cable resistance around 15 ohms or less; the sensor can be up to 300 m (984 ft) away, but corrosion or a marginal splice along that run will show up as drift.
• Confirm grounding. RTDs may be grounded or ungrounded; a wiring change that alters that can shift readings.
• Look at the terminal board and power. A loose DC-37 seating, a tired TRTD board, or a dropped power feed can mimic a pack failure.
• Read the LEDs and ToolboxST diagnostics. The Power and ATTN lamps plus the controller's alarm log usually tell you whether you are chasing a pack, a configuration mismatch, or a field problem.

If all of that checks out and the pack is still unresponsive, a known-good IS220PRTDH1A is a reasonable next step.

How the H1A Suffix Fits the IS220 Numbering

Break the number into blocks: IS220 designates a Mark VIe distributed I/O pack, PRTD is the RTD-input function, and H1A is the group and revision. The letter at the end advances with hardware revisions, so an H1A sits earlier in the sequence than an H1B while remaining the same functional pack. Match both the suffix and the printed revision when you replace one. Our GE Speedtronic Part Number Decoder lays the convention out block by block.

Companion Packs and Cross-Generation Notes

Temperature monitoring in a Mark VIe system is usually split between RTD packs like this one and thermocouple packs such as the PTCC. If your site is migrating from an earlier platform, Mark V vs Mark VI: DS200 to IS200 is a helpful primer. Browse related hardware under GE Mark VI IS200 Boards and the broader GE Speedtronic Turbine Control Boards collection.

Details That Speed Up Your Quote

• Full part number and suffix (IS220PRTDH1A) plus the revision on the label.
• A photo of the label and, if useful, the terminal board it mounts on.
• Turbine model and Mark VIe generation.
• Quantity and required delivery timing.

Get Your IS220PRTDH1A Quote in 24 Hours

This unit is a new-surplus, factory-packaged open-box IS220PRTDH1A, covered by the warranty noted below. Click Request a Quote and we will respond within 24 hours. We ship worldwide on DDP terms and welcome purchase orders.