Product Core Brief

• Model: IS220PRTDH1A
• Brand: General Electric (GE)
• Series: Mark VIe (Speedtronic)
• Core Function: High-precision Resistance Temperature Device (RTD) input module that converts physical temperature changes into digital signals for the Mark VIe controller, supporting up to 8 RTD channels with 14-bit A/D resolution.
• Product Type: PRTD RTD Input Module (I/O Pack)
• Key Specs: 8 isolated RTD input channels | 14-bit A/D resolution | 2/3/4-wire RTD support | Dual redundant Ethernet ports | 28VDC power | -30°C to +65°C operating range | Hazardous location rated
• Condition: New Original / New Surplus

Product Introduction

The GE IS220PRTDH1A is a Resistance Temperature Device (RTD) input module in GE’s Mark VIe Speedtronic control system, serving as the critical temperature monitoring interface for gas turbine, steam turbine, and industrial process control applications. It is the “sensory nerve ending” of the Mark VIe system, converting resistance changes from RTD sensors into digitized temperature data that the controller uses for real-time monitoring, protection, and control.

The module provides 8 independent RTD input channels, each supporting 2-wire, 3-wire, or 4-wire RTD connections. The 3-wire and 4-wire configurations provide automatic lead resistance compensation (up to 15Ω), eliminating measurement errors caused by long cable runs between the sensor and the control cabinet. The 14-bit A/D converter delivers high-resolution temperature readings, enabling the controller to detect subtle temperature changes that could indicate bearing wear, combustion imbalance, or coolant flow issues.

The IS220PRTDH1A communicates with the Mark VIe processor (such as the UCSAH or UCSBH series) via dual redundant 10/100Mbps Ethernet ports (IONet), ensuring that temperature data continues to reach the controller even if one network cable fails. The module connects to a compatible terminal board (TRTD or SRTD series) via a DC-37 pin connector, which routes the RTD field wiring to screw terminals for easy installation and maintenance.

The module is approved for use in hazardous locations (Class 1, Division 2, Groups A, B, C, D and Class 1, Zone 2) when paired with compatible terminal boards (IS200TRTDH2D, IS200SRTDH1A, or IS200SRTDH2A), making it suitable for installation in turbine enclosures and other areas where flammable gases or vapors may be present. Front-panel LEDs provide at-a-glance diagnostics for power, communication, and fault status on each Ethernet port.

Key Technical Specifications

Quality Control Process

Every IS220PRTDH1A goes through a full functional bench test before it ships. We start with a visual PCB inspection — checking for cold solder joints, burnt traces, swollen capacitors, and verifying the integrity of the DC-37 pin connector and both RJ45 Ethernet jacks. RTD input modules are sensitive to contamination on the analog input traces, which can cause measurement drift over time.

Then we power it up on a regulated 28VDC supply and verify the power draw is within the 0.24A spec. We test each of the 8 RTD input channels by injecting precision resistance values (simulating PT100 or PT1000 RTD sensors at multiple temperature setpoints) and comparing the digitized output against NIST-traceable reference values, confirming accuracy within the module’s specified tolerance. We verify the lead resistance compensation function by adding known resistance values to the lead wires and confirming the module correctly compensates for the added resistance.

We test both Ethernet ports by connecting to a network switch and confirming link/activity LEDs illuminate on each port, then verifying the module registers on the IONet with its correct hardware ID. We test the redundant communication function by disconnecting one Ethernet cable and confirming the module continues to communicate over the remaining link without data loss. We verify the front-panel LED diagnostics by confirming the Power, ATTN, and Ethernet port LEDs respond correctly to various conditions. Finally, we confirm the module is compatible with the specified terminal boards (TRTD/SRTD series) by performing a physical connection test. Each unit ships in anti-static foam with a moisture barrier bag.

Replacement Pitfall Guide

❗ Verify the terminal board compatibility before installation. The IS220PRTDH1A is only compatible with specific terminal boards: IS200TRTDH2D, IS200SRTDH1A, and IS200SRTDH2A. It is NOT compatible with DIN-rail mounted DRTD boards. If you attempt to connect it to an incompatible terminal board, the module will detect the mismatch and may refuse to operate. Always confirm the terminal board model before ordering the replacement.

❗ Confirm the RTD wiring configuration matches your field sensors. The module supports 2-wire, 3-wire, and 4-wire RTD connections, but the terminal board must be wired to match your field sensor configuration. A 3-wire RTD sensor connected to a 2-wire terminal configuration will produce inaccurate temperature readings due to uncompensated lead resistance. Verify the wiring configuration in the field and on the terminal board before connecting.

❗ Check the scan rate setting matches the terminal board version. The TRTDH1D terminal board provides filtering compatible with the PRTD’s standard scan rate, while the TRTDH2D provides less filtering for the PRTD’s fast scan rate. If you install the PRTD on an earlier-version TRTD board with the fast scan rate enabled, the module will detect the incompatibility and report a fault. Verify the scan rate setting in the ToolboxST configuration software matches your terminal board version.

❗ Don’t ignore the lead resistance compensation limit. The module compensates for up to 15Ω of lead resistance. If your RTD cable run is very long and the total lead resistance exceeds 15Ω, the compensation will be incomplete and temperature readings will be inaccurate. For long cable runs, use 4-wire RTD connections (which are less sensitive to lead resistance) or relocate the module closer to the sensors.

❗ Verify the hazardous location rating if applicable. If the module is installed in a hazardous location (Class 1, Div. 2 or Zone 2), confirm that the terminal board is also rated for the same hazardous location. Using a non-rated terminal board in a hazardous area violates safety standards and may void insurance coverage.

❗ Watch for Ethernet cable routing issues. The dual Ethernet ports provide redundant communication, but both cables must be routed through separate physical paths to provide true redundancy. If both cables run through the same cable tray and that tray is damaged, you lose both communication paths simultaneously. Route the primary and backup Ethernet cables through separate conduits or cable trays.

Keep these in mind and you’ll cut 90% of rework time.

Compatibility Matrix & Benchmarks

• Channel Count: 8 isolated RTD inputs per module
• Resolution: 14-bit A/D for high-precision temperature measurement
• Redundancy: Dual Ethernet ports for fault-tolerant communication