IS220PAICH1A: Analog I/O Pack for the GE Mark VIe IONet

This listing is a used, cleaned and tested IS220PAICH1A carrying the REV. C board revision. The IS220PAIC is the analog I/O pack in GE's Speedtronic Mark VIe (and Mark VIeS) distributed control architecture. It does not sit in a rack — it mounts directly on an analog input terminal board (TBAI/STAI-type) through a single DC-37 pin connector, and it talks back to the <R>, <S>, or <T> controller over the I/O Ethernet network (IONet) through dual RJ-45 ports. The pack carries a processor board common to all Mark VIe I/O packs plus an acquisition board dedicated to the analog function.

On the field side, the PAIC handles 10 analog inputs and 2 analog outputs — 12 channels per terminal board. The first eight inputs are configurable as 5 V, 10 V, or 4-20 mA current loop; the last two accept ±1 mA or 4-20 mA. The current-loop load resistors physically live on the terminal board, not on the pack — the pack only senses the voltage across them. Both outputs on this H1 pack are 0-20 mA current loop. Conversion runs through a 16-bit A/D converter on the input side and a 14-bit D/A converter on the output side, with a normal scan time of 5 ms (200 Hz).

Before You Order: Confirm the Fault Is Actually in the Pack

An analog reading that has drifted, frozen, or gone to a fault value is not automatically a bad PAIC. Because the pack only measures what the terminal board presents to it, the most common root causes of a "bad analog input" sit upstream of the pack:

• Field wiring and load resistors — these live on the terminal board. A drifted or open resistor, a loose field terminal, or a failing transmitter produces exactly the same symptom as a failed input channel on the pack.
• The swap test — move the suspect PAIC to a known-good terminal board (or a known-good pack onto the suspect board). If the fault follows the pack, replace the pack. If it stays with the board, the terminal board or its field wiring is the real problem. This is the standard field method used on Mark VIe I/O packs before any hardware is condemned.
• IONet health — check both ENET1/ENET2 links, inspect connectors for corrosion, and rule out a switch problem. A lost network path can present on the operator screen exactly like a failed pack.
• Terminal board revision match — powering a PAIC on an unsupported or older terminal board revision can trigger a system compatibility alarm that looks like a fault but is really a mismatch, not a hardware failure.
• Genuine pack-level alarms — a suicide-relay or output-stage alarm on an analog output channel does point to the pack's acquisition board itself; that is one of the few cases where the pack is the correct part to replace.

Reading the IS220PAICH1A Part Number

IS220 identifies the part as a Mark VIe distributed I/O pack; PAIC is the functional acronym for the analog I/O pack; H1 marks the base design generation with two 0-20 mA current outputs (the H2 generation adds a 0-200 mA output option); the trailing letter (A, B) marks a processor/hardware revision, and REV. C marks the board revision within this specific part number. None of these are cosmetic — the revision has to match what your terminal board and your ControlST/ToolboxST project expect. For the full logic behind GE's Speedtronic numbering, see our GE Speedtronic Part Number Decoder.

Related Packs and Terminal Boards

The PAIC mounts on analog input terminal boards in the TBAI/STAI family (it is not compatible with the DIN-rail mounted DTAI board). If your panel uses discrete I/O instead of analog on the same IONet segment, you'll be looking at the related PDIA (contact input) or PDOA (discrete output) packs rather than PAIC. Browse our full GE Mark VI IS200 Boards collection to cross-check terminal boards and companion packs, or see our GE Speedtronic Turbine Control Boards collection for the wider Mark V/Mark VI/Mark VIe range.

What to Include in Your Quote Request

• Full part number with suffix and revision (e.g., IS220PAICH1A REV. C)
• A photo of the physical label on the pack, if possible
• Turbine model and Mark control generation (Mark VI, VIe, or VIeS)
• Quantity needed
• Urgency — planned outage or unplanned downtime

Send us those details and we will send back a quote within 24 hours. AloTechParts ships worldwide on a DDP basis and accepts purchase orders — every order is quoted and confirmed with a person, never checked out at a listed price. Request a Quote to get started.

General Information about the Product
Part Number	IS220PAICH1A Mark VI IS220
Description	GE General Electric IS220PAICH1A REV. C Power Distribution Pack Mark VI
Condition	used Clean and Tested. With 1 Year Warranty.