IS220PPROH1A: the backup turbine protection I/O pack

The IS220PPROH1A is a backup turbine protection (PPRO) I/O pack in the GE Speedtronic Mark VIe system. It belongs to the independent protection path — the <P> side of the control — and works with its terminal boards to provide an independent backup overspeed protection function, a backup check on generator synchronizing to the utility bus, and an independent watchdog over the primary control. In short, it is a safeguard that stands apart from the main turbine control so that a single failure in the primary path does not defeat protection.

The pack carries a high-speed processor, two independent 10/100 Ethernet ports for IONet, a hardware reset circuit, a watchdog timer, and an internal temperature sensor. Its faceplate groups the LEDs in pairs: PWR with ATTN, then a LINK/TxRx indication with ENET1, and another LINK/TxRx with ENET2, with the infrared port at the bottom.

Where the PPRO lives in the Mark VIe protection path

The PPRO does not act alone; it mounts on a protection terminal board and connects onward to an emergency trip terminal board. In a triple-redundant scheme, three PPRO packs are used across the <R>, <S>, and <T> networks — either mounted on separate simplex protection (SPRO) terminal boards or together on a TMR TPRO-type terminal board. From there a DC-37 cable runs to the emergency trip board that suits the machine: TREG for gas turbines, TREL for large steam turbines, TRES for small and medium steam turbines, or TREA for aeroderivative units. The exact terminal-board set reflects how your plant protection scheme was engineered, so match what is installed rather than assume.

Diagnosing before you buy — without touching the trip settings

Because the PPRO sits in the trip chain, treat troubleshooting differently from an ordinary I/O pack. Do not bench-test, force, or defeat a protection pack, and do not attempt to set or verify trip levels from a product description. Any setpoint, functional testing, or redundancy verification must follow the GE Mark VIe manual (GEH-6721) and your plant's own protection and lockout procedures. With that boundary respected, the pre-purchase question is simply whether the pack itself is the fault, and these are the usual look-alikes:

• Speed-sensing field wiring and pickups: the magnetic speed probes and their cable runs (GE limits voltage-sensing wiring to 1,000 ft of 18 AWG) can fail in ways that flag as a protection problem.
• Protection and trip terminal boards: the SPRO/TPRO board, the emergency trip board (TREG/TREL/TRES/TREA), and the DC-37 cable between them are all suspects before the pack.
• A single <R>, <S>, or <T> leg: a discrepancy on one leg is frequently an IONet cable, network, or terminal issue on that leg rather than a bad pack.
• Power feed: confirm the PWR/ATTN LED pair and the ENET link indications before condemning the electronics.

Use ToolboxST diagnostics and your site protection procedure to confirm the pack is genuinely at fault, and coordinate any removal from service with operations — never pull a protection pack from a running machine on a hunch.

Part number, the H1A suffix, and the BPPB processor

The number reads as IS220 (Mark VIe distributed I/O platform), PPRO (turbine protection function), and H1A (hardware revision and variant). The PPROH1A is built on the BPPB processor board. A later variant, the PPROS1B, uses a functionally compatible BPPC processor and requires ControlST V04.07 or later; note that switching between BPPB and BPPC packs cannot be auto-reconfigured. For protection hardware especially, order the exact designation you are replacing and verify software compatibility. Our GE Speedtronic Part Number Decoder breaks down the fields.

Terminal boards and related protection hardware

Protection packs are usually sourced as part of a matched set with their terminal boards. See the GE Mark VI IS200 Boards and GE Speedtronic Turbine Control Boards collections for protection and emergency-trip boards along with the servo, analog, and discrete packs on the same IONet. If you are comparing protection across control generations, the Mark V vs Mark VI: DS200 to IS200 guide provides context.

What to include in your IS220PPROH1A quote request

Protection spares need to match precisely, so please send:

• The full part number with suffix (IS220PPROH1A) and the revision on the label.
• A clear photo of the pack nameplate.
• Your turbine model and Mark VIe generation, and the emergency-trip terminal board in use (TREG/TREL/TRES/TREA) if known.
• Quantity and urgency, including any outage date.

This unit is used, clean and tested, with a 1-year warranty; the exact condition wording is in the table below.

Request a quote for the IS220PPROH1A

Use Request a Quote with the information above and we will respond within 24 hours. We ship worldwide on DDP terms and accept purchase orders from qualified organizations.