GE IS220PPROH1A Mark VIe Backup Turbine Protection I/O Pack

The GE IS220PPROH1A is a Backup Turbine Protection (PPRO) I/O Pack designed for the Mark VIe turbine control system. It provides independent backup overspeed protection, generator synchronization checking, and watchdog monitoring of the primary control system. The module works with dedicated protection terminal boards to process turbine speed and trip-related signals independently of the primary turbine control functions.

Functional Description

The IS220PPROH1A provides a separate protection path for turbine overspeed and emergency trip functions. It monitors three turbine speed signals and exchanges status information with the associated protection terminal board.

Its protection functions include:

• Independent backup overspeed protection.
• Backup generator synchronization checking against the utility bus.
• Watchdog monitoring of the primary control system.
• Monitoring of protection terminal board feedback signals.
• Activation of backup trip relays when configured protection conditions are detected.

The PPRO pack communicates with Mark VIe control modules through IONet Ethernet connections. Its independent protection arrangement allows backup trip functions to operate without relying on normal primary control execution.

Protection Architecture and Terminal Board Configuration

The module supports simplex and Triple Modular Redundant (TMR) protection arrangements. A typical TMR configuration uses three PPRO packs with the appropriate SPRO or TPRO terminal board arrangement.

The documented accessory terminal boards for the IS220PPROH1A are:

• IS200SPROH1A
• IS200SPROH2A
• IS200TPROH1C
• IS200TPROH2C
• IS200TREAH1A
• IS200TREAH3A

The terminal board determines the field signal connections and protection configuration. The associated emergency trip board and interconnecting cable must also match the installed turbine protection architecture.

Technical Specifications

Electrical Ratings and Signal Processing

The PPRO pack receives turbine speed signals through its associated SPRO, TPRO, or TREA terminal board configuration. The documented electrical range for speed inputs is -15 to +15 VDC. When used with SPRO or TPRO boards, potential transformer inputs support 0-138 VAC at 5-66 Hz.

For TREA configurations, the module also supports voltage detection inputs of 16-140 VDC and emergency-stop inputs of 18-140 VDC. These signal ranges depend on the selected terminal board and should not be interpreted as universal inputs available in every configuration.

The TREA contact output is rated up to 28 VDC and 7 A DC. With TPRO configurations, the speed sensor power output is nominally 24 VDC, with a maximum rated current of 25 mA.

Frequently Asked Questions

Q: Is the IS220PPROH1A a standard Mark VIe I/O module or a dedicated protection module?

A: It is a dedicated backup turbine protection I/O pack. Its PPRO functions provide independent overspeed protection, synchronization checking, and primary controller watchdog monitoring rather than general-purpose process I/O.

Q: Which terminal boards are compatible with the IS220PPROH1A?

A: The documented accessory terminal boards are IS200SPROH1A, IS200SPROH2A, IS200TPROH1C, IS200TPROH2C, IS200TREAH1A, and IS200TREAH3A. The correct board depends on the required simplex or TMR protection arrangement.

Q: What power supply does the IS220PPROH1A require?

A: Its specified nominal supply is 28.0 VDC, with an operating supply range of 27.4-28.6 VDC and a maximum current rating of 0.37 A DC.