GE IS220PPROS1B | PPROS1B | EMERGENCY TURBINE PROTECTION I/O PACK.IS220PPROS1B is an Emergency Turbine Protection I/O Pack manufactured and designed by General Electric as part of the Mark VIe Series used in GE Distributed Control Systems. A backup Overspeed protection system with a backup check for generator synchronization to a utility bus is provided by the Emergency Turbine Protection I/O pack (PPRO) and related terminal boards. They also serve as the primary control's independent watchdog. Three triple modular redundant (TMR) PPRO I/O packs mounted to a separate simplex protection (SPRO) terminal board make up a typical protection system. Each SPRO is connected to the designated emergency trip board by a cable with DC-37 pin connections on both ens:

TREG: Gas Turbine Emergency Trip Terminal Board.

TREL: Large Steam Turbine Emergency Trip Terminal Board.

TRES: Small/Medium Steam Turbine Emergency Trip Terminal Board.

TREA: Turbine Emergency Trip Terminal Board.