IS220PPRAS1B GE MKVIe, IO PACK, PROTECTION - AERO, BPPC

Description:

The IS220PPRAS1B is an Emergency Turbine Protection I/O Pack developed by GE. It provides an independent backup overspeed protection mechanism and a separate watchdog function for principal control and isolated trip contact input. 

This device is the successor to the standard Mark VIe PPRO Emergency Turbine Protection I/O pack, which required new hardware and modified code to provide six speed inputs when dual speed sensors per shaft are fanned to three protective I/O packs. The majority of its settings, parameters, and behavior are the same as those in the PPRO. However, only the TREA terminal board with the WREA option board supports PPRA. Other settings that PPRO supports cannot be used with PPRA.

In order to communicate with the control modules through IONet, PPRA has an Ethernet connection. The primary and backup trip prevention systems for the Mark VIe control are designed to work together at the trip terminal board level. The Turbine Primary I/O pack (PTUR), when connected with PPRA/TREA, operates a primary trip board (usually TRPA), providing primary protection. A TREA terminal board installed with PPRA offers backup protection. For firmware overspeed, acceleration, deceleration, and a hardware implemented overspeed protection, PPRA supports six speed signals (specified as three sets of speed pairs). It monitors how the main control is working.

A wide range of feedback signals are used by PPRA to track the state and functionality of the TREA trip board. If a fault is found, PPRA will trip the backup trip relays on the TREA board and initiate a trip on the primary control. PPRA is completely unrelated to and unaffected by the main control process.

To properly function, only three I/O packs are needed for PPRA mounted on TREA with WREA. In systems with a single controller or dual controllers, all networks should be linked to the PPRA. In systems with three controllers, all networks should also be linked to the PPRA.

To set up the I/O pack, secure the TREA terminal board in place and connect three I/O packs directly to it. Insert the threaded posts into the terminal board mounting bracket's slots and adjust the bracket's position so that everything is properly connected. Connect one or two Ethernet wires depending on the system configuration. Connect the module to the power supply by plugging in the power connector on the side. Soft-start functionality is built into the I/O module which controls current levels when it is used. Configure the module using ToolboxST program as needed.

The processor board is connected to the I/O pack or module function-specific acquisition board. When input power is applied, the soft-start circuit ramps up the voltage available on the processor board. After finishing self-test routines, it loads application code from flash memory specific to each I/O pack or module type. To ensure correct matching of application code, acquisition board, and terminal board, it reads board ID information. When there is a good match, it attempts to start Ethernet connections by requesting a network address using DHCP and the terminal board's unique identifier. After Ethernet startup, the CPU runs applications, programs on-board logic, and allows acquisition boards to start working.

Auto-Reconfiguration enables operators to swap I/O packs without manually reconfiguring each pack or module. When Auto-Reconfiguration is activated, a reconfiguration file is automatically downloaded from the controller to the I/O pack when it detects an I/O pack booting with different configurations. The controller won't allow reboot while auto-reconfiguration is running; it must complete before another can begin. No additional downloads can be started while auto-reconfiguration is ongoing. Only diagnostics are performed if an I/O pack is already active during auto-reconfiguration. Through ToolboxST's Component Editor, auto-reconfiguration can be turned on or off allowing manual adjustments if necessary. Replacing a terminal board requires manual reconfiguration of the I/O pack since terminal boards and controllers cannot auto-reconfigure. Follow installation steps to install or replace an I/O pack which boots up when power is connected starting Auto-Reconfiguration process by sending a signal to let the controller know it needs an IP address and configuration. The controller queries the I/O pack for existing files to decide whether reconfiguration is needed then begins downloading reconfiguration files and IP address. Once download is finished, the controller sends a signal to the I/O pack which restarts and performs self-diagnostics then connects to the internet.

The hardware for the emergency trip function is included on an internal application-specific circuit board in the I/O pack. The application board is shared by both the PPRA and PPRO I/O packs and connects the processor to the TREA terminal board. An option card header on the application board connects to a specific option card.
Not all of the signal conditioning is utilized in the PPRA. Three more pulse rate input channels and support for the speed pulse rate repeater outputs are added via the option card linked to the internal header. Every board in the pack has electronic ID components that can be read when electricity is applied. The CPU may verify that the I/O pack is correctly matched to each terminal board connector using a similar part, and it can also transmit the board revision status to the system-level control.

The terminal board is connected to the IO pack through a DC-62 pin connector on the underside.
The primary IONET-EGD connection is an RJ45 Ethernet connector on the side of the pack labeled ENET1.
The pack and terminal board are powered by a 28 V dc power connector on the side of the pack.
Direct or Conditional Discrete Input Trip
The TREA+WREA board's four isolated discrete contact input trip signals are supported by PPRA. While Contact # and L5Cont #_Trip are implemented in hardware logic, the direct/conditional determination is done in firmware. The firmware is not in the trip path when set up for direct trip. When set for conditional trip, the firmware assesses the communication health (represented by network keepalive) and inserts the conditional signal from signal space into the programmable logic. The default will allow any conditional trip in the event that controller connectivity is lost.

On the three values that come out of the high-speed choice, it executes firmware Overspeed protection. While the three inputs are referred to as HP, IP, and LP in the PPRA specification, the three inputs are free to be used as needed in a system design. 

Datasheet Link:

IS220PPRAS1B GE MKVIe, IO PACK, PROTECTION - AERO, BPPC PDF Datasheet