IS220PAICH1A: What This Pack Actually Does
You'll sometimes see the IS220PAICH1A listed under generic labels like "power distribution pack" — in GE's own Speedtronic documentation, PAIC is the analog I/O pack for the Mark VIe (and Mark VIeS) control system, not a power distribution component. It provides the electrical interface between the I/O Ethernet network (IONet) and an analog input terminal board, mounting directly onto that board through a single DC-37 pin connector rather than living in a card rack.
Inside the pack, a processor board shared across all Mark VIe distributed I/O packs works alongside an acquisition board built for analog signals: 10 analog inputs (the first eight switchable among 5 V, 10 V, or 4-20 mA current loop; the last two switchable between ±1 mA and 4-20 mA) and 2 current-loop outputs at 0-20 mA on this H1 generation. A 16-bit A/D converter and 14-bit D/A converter handle the conversion, with a normal scan time of 5 ms (200 Hz). Dual RJ-45 ports connect the pack to the <R>, <S>, or <T> controller, and a 3-pin connector supplies 24-28 V dc power with built-in soft-start current limiting.
Diagnose the Chain Before You Replace the Pack
A suspect analog value can come from several places between the field device and the controller, and the PAIC pack is only one of them:
- The load resistors for current-loop inputs sit on the terminal board, not inside the pack — a resistor drifting out of tolerance looks identical to a pack-side input failure.
- Swap the pack onto a known-good terminal board (or install a known-good pack on the suspect board). Wherever the fault goes is the part you replace. This single test saves more unnecessary pack purchases than anything else.
- Verify both IONet Ethernet links are actually up and the switch feeding them is healthy — a communications alarm from a bad cable or switch reads the same as a pack failure on the operator screen.
- Check that the terminal board revision is one this pack supports. An unsupported revision throws a compatibility alarm; it is not a sign the pack has failed.
- A suicide-relay or output-stage alarm on an analog output is one of the few symptoms that reliably points to the pack's own acquisition board rather than the field side.
Understanding the Part Number
IS220 designates a Mark VIe distributed I/O pack; PAIC is the analog I/O function; H1 is the base output generation (two 0-20 mA outputs, versus the 0-200 mA option added on H2 packs); the trailing letter marks a processor/hardware revision. Suffix and revision both need to match your terminal board and ControlST configuration — they are not interchangeable labels. Our GE Speedtronic Part Number Decoder covers the full naming logic if you want to double-check what's on your existing label before ordering.
Related Packs and Terminal Boards
The PAIC pairs with TBAI/STAI-family analog terminal boards. For discrete rather than analog signals on the same IONet segment, look at the related PDIA (contact input), PDOA (discrete output), or combined PDIO packs. Our GE Speedtronic Turbine Control Boards collection covers the wider Mark V/VI/VIe range if you need to cross-check what else is on the panel.
Information to Include in Your Quote Request
- Full part number with suffix (IS220PAICH1A) and any revision letter on the label
- A photo of the label itself
- Turbine model and Mark control generation
- Quantity
- Whether this is for planned maintenance or an unplanned outage
We reply to every quote request within 24 hours, ship worldwide DDP, and accept purchase orders. There is no checkout price on this site by design — every order is quoted and confirmed directly with our team first.
General Information about the Product |
Part Number |
IS220PAICH1A Mark VI IS220 |
Description |
IS220PAICH1A By GE I/O Analog Power Distribution Pack |
Condition |
used Cleaned and Tested. With 1 Year Warranty |
