New Surplus IS220PAICH1A: Factory-Packaged Analog I/O Pack

This IS220PAICH1A is offered as new surplus factory package (NSFP) — unused stock in its original factory packaging rather than a pulled-and-tested used unit. For a spares program that wants shelf-ready inventory without waiting on repair turnaround, that distinction matters. Functionally, it is the same PAIC pack used throughout GE's Speedtronic Mark VIe (and Mark VIeS) fleet: the analog I/O pack that mounts directly on an analog input terminal board and communicates with the <R>, <S>, or <T> controller over IONet through dual RJ-45 ports and a single DC-37 pin connector to the board.

The pack pairs a processor board common to every Mark VIe I/O pack with an acquisition board built for analog signals. It reads 10 analog inputs — eight configurable to 5 V, 10 V, or 4-20 mA current loop, and two more configurable to ±1 mA or 4-20 mA — and drives 2 current-loop outputs at 0-20 mA on this H1 generation, through a 16-bit A/D converter and 14-bit D/A converter at a 5 ms (200 Hz) normal scan rate. The current-loop load resistors are mounted on the terminal board itself, which is worth knowing before you assume a reading problem sits inside the pack.

Before You Install a Replacement, Confirm Where the Fault Actually Is

• Start at the terminal board: field wiring and load resistors live there, and a drifted resistor or loose terminal produces the same symptom as a bad channel on the pack.
• Do the swap test whenever possible — move the old pack to a known-good terminal board, or install a spare pack on the suspect board, and see which one the fault follows. This is the fastest way to avoid installing a new pack that doesn't fix anything.
• Check the IONet path: both Ethernet ports, cable and connector condition, and the switch. A dropped network connection can mimic a dead pack from the operator station.
• Verify terminal board revision compatibility before installing this pack — a mismatch generates a compatibility alarm rather than working around the issue silently.
• If the actual alarm is a suicide-relay or output-stage fault on an analog output, that does point at the pack's own acquisition board, and installing a replacement pack is the correct fix.

What IS220PAICH1A Tells You

IS220 marks this as a Mark VIe distributed I/O pack; PAIC identifies the analog I/O function; H1 is the base design generation with two 0-20 mA current outputs; the trailing A marks the original hardware/processor revision (later packs carry a B, built around a different processor board). Confirm the full string, not just the PAIC prefix, against your terminal board and ControlST project. Our GE Speedtronic Part Number Decoder explains how each segment of a Speedtronic part number is built.

Related Packs and Boards

PAICH1A mounts on TBAI/STAI-type analog terminal boards. If your panel also has discrete I/O on the same IONet segment, the related packs are PDIA (contact input), PDOA (discrete output), and PDIO (combined discrete I/O). See our GE Mark VI IS200 Boards collection to check compatible terminal boards and neighboring part numbers.

Speed Up Your Quote

• The full part number and suffix (IS220PAICH1A) plus any revision letter visible on your existing unit
• A photo of the label
• Turbine model and Mark control generation
• Quantity needed
• Urgency of the request

Send us that information and we'll respond with a quote within 24 hours. AloTechParts ships worldwide DDP and accepts POs; as a request-a-quote store we don't publish prices online, so every order is confirmed with a person before it ships.