IS220PPROS1B backup and emergency turbine protection pack

Listed by GE as a backup turbine protection (PPRO) I/O pack and often applied in emergency-trip service, the IS220PPROS1B is the BPPC-based revision of the Mark VIe protection pack. It forms part of the turbine's independent protection layer, providing a backup overspeed function, a backup synchronizing check to the utility bus, and an independent watchdog on the primary control. The point of the PPRO is separation: it is engineered to act even if the main control path is compromised, which is why it runs on its own hardware and its own IONet connections.

Independent overspeed, sync-check, and watchdog roles

Each PPRO pack has a high-speed processor, two fully independent 10/100 Ethernet ports, a watchdog timer, a hardware reset circuit, and an onboard temperature sensor. In a triple-redundant protection scheme, three packs are deployed on the <R>, <S>, and <T> networks and mounted either on individual simplex protection (SPRO) terminal boards or on a TMR TPRO-type board, with a DC-37 cable carrying the trip signals to the emergency trip terminal board. Beyond that architecture, the specifics of how protection is armed, tested, and voted are defined by the GE Mark VIe manual (GEH-6721) and your plant's protection scheme — they are not something to infer from a listing, and this description does not attempt to.

Ruling out field and terminal-board causes first

When a protection channel flags, the pack is only one of several possible causes, and on a trip system you want to be certain before you touch anything. Keeping strictly to diagnosis rather than testing, check:

• Speed pickups and their wiring: magnetic speed sensors and long field runs are a common source of protection faults; GE limits voltage-sensing wiring to 1,000 ft of 18 AWG.
• Terminal and trip boards: the SPRO or TPRO board, the emergency trip board (TREG, TREL, TRES, or TREA), and the interconnecting DC-37 cable.
• One network leg: a fault seen on a single <R>, <S>, or <T> leg often traces to that leg IONet cabling or terminal rather than the pack.
• Power and LEDs: read the PWR/ATTN pair and ENET link indications to separate a supply or network problem from an electronics failure.

Confirm any conclusion through ToolboxST diagnostics and your site protection procedure, and schedule work with operations. A protection pack should never be removed, forced, or tested outside those procedures.

The S1B suffix, BPPC, and ControlST compatibility

Read the number as IS220 (Mark VIe distributed I/O platform), PPRO (turbine protection function), and S1B (hardware revision and variant). The PPROS1B carries the BPPC processor board and is supported by ControlST software V04.07 and later; the earlier PPROH1A used the BPPB. Switching between BPPB and BPPC packs cannot be auto-reconfigured, so a change is a planned activity rather than a drop-in. If your label shows an additional trailing character, that indicates a further hardware revision — match the full designation exactly. Our GE Speedtronic Part Number Decoder explains the numbering.

Companion protection boards (SPRO, TPRO, TREG/TREL/TRES/TREA)

Because the PPRO only functions with its terminal and trip boards, plan spares as a set. The GE Speedtronic Turbine Control Boards and GE Mark VI IS200 Boards collections list protection terminal boards and emergency-trip boards alongside the servo, analog, and discrete packs that share the IONet. Comparing protection between control generations? The Mark V vs Mark VI: DS200 to IS200 guide is a helpful reference.

Details to include when requesting a quote

Send us:

• The complete part number and suffix exactly as printed (IS220PPROS1B and any trailing revision).
• A photo of the unit label.
• Turbine model, Mark VIe generation, and the emergency-trip board type if known.
• Quantity and required timing.

This item is new surplus in the factory package; the exact condition and warranty are shown in the table below.

Request your IS220PPROS1B quote — 24-hour turnaround

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