Overview
The Woodward ProTech SX Simplex System is a single channel turbine safety protection system designed to provide overspeed, over acceleration, stall, and other configurable logic protections. This system is suitable for steam turbines driven by mechanical or power generation, and has the characteristics of high reliability, strong configurability, and support for online testing and diagnosis. It is a key equipment to ensure the safe operation of steam turbines.
Main functions and protective features
Overspeed Trip Protection
Overacceleration Trip Protection
Speed Loss Trip
Speed Fail Trip protection
Configurable Logic Protection
Event recording and logging function
Online testing and diagnosis
Redundant speed input support (dual redundancy mode)
System composition and interface
1. Front panel interface
ProTech SX provides an intuitive front panel interface, including:
4.3-inch LCD display screen
Soft key navigation
Status indicator lights (Trip, Alarm, Unit Health)
Physical buttons (ESC, HOME, START, RESET, directional keys) ENTER、VIEW)
2. Menu Structure
The system provides four main menus:
Monitor Menu: Real time monitoring of speed, acceleration, input status, logic status, etc.
View Logs: View event logs (overspeed, trip, alarm, event records, etc.).
Config Menu: Configure parameters such as speed, trip, analog output, test mode, etc.
Test Menu: Perform overspeed testing, simulated speed testing, user-defined testing, etc.

Core configuration function
Speed management
Speed redundancy mode: single speed or dual redundant speed input.
Maximum speed difference: The maximum speed difference allowed in dual redundancy mode.
Redundant speed loss action: trip or alarm.
Overspeed trip set value: 100-32000 RPM.
Acceleration trip: Can be enabled/disabled, set the enabled speed and trip value.
Configurable input
The system provides 7 configurable inputs, supporting:
Discrete Input
Analog input (4-20 mA)
Can set engineering units, measurement ranges, and high/low alarm points
Logic programming function
ProTech SX has a built-in configurable logic module that supports:
50 logic gates (AND, OR, NOT, NAND, NOR, XOR, XNOR) in total
10 Latch latches in total
There are a total of 15 delay devices
10 comparators in total
There are a total of 15 timers
There are a total of 10 Unit Delay devices
2 Trip Cycle Timer in total
Trip and alarm latch
Trip latch: Supports 25 user configurable trip inputs that can be named.
Alarm latch: Supports 50 users to configure alarm inputs.
Event locking: There are a total of 3 groups, each with 25 inputs, supporting "initial" recording.
Output configuration
3 programmable relay outputs: configurable drive signal and polarity.
1 4-20 mA analog output: configurable speed and current correspondence.
Test mode
ProTech SX provides multiple online testing functions without the need for downtime:
Temporary overspeed setting value test: Use actual speed signals to test overspeed protection.
Manual simulation speed test: Use an internal frequency generator to manually adjust the speed.
Automatic simulation speed test: Automatically rise to the overspeed point to trigger a trip.
User defined testing: There are 3 groups in total, with configurable startup, reset, and timeout logic.
Lamp test: Verify the functionality of the front panel LED.
Programming and Configuration Tools (PCT)
The system is equipped with a PC programming and configuration tool (PCT), which supports:
Offline programming: Create, edit, and save configuration files (in. wset format).
Online configuration: Connect to ProTech SX to modify parameters in real-time.
Log export: Trip, alarm, event, and overspeed logs can be exported as HTML files.
Configuration comparison: Compare the differences between two configuration files.
CRC check: Provide CRC values for each configuration block for version management.
PCT operation level
Isolation level: No need to connect devices, editable configuration files.
Test level: Can view logs, export configurations, reset logs (excluding peak speed/acceleration).
Configuration level: Can upload/download configuration files and modify all parameters.
Communication and Interface
Modbus RTU: Supports RS-232/RS-485, slave mode.
Time synchronization: Supports 24-hour time synchronization signal input.
Service port: RS-232, used for PCT connection.
Security and Certification
Meets NERC network security requirements: supports two-level password protection (Test/Config).
Password strategy: 6 characters, supporting uppercase and lowercase letters, numbers, and special symbols.
Default password: AAAAAA (recommended to change after first use).
Typical application scenarios
Power plant turbine overspeed protection
Industrial driven turbine safety system
Compressor and pump drive protection
Can be used as an independent security system or integrated into DCS/PLC
Summary of Technical Specifications
Project Parameters
Speed measurement range 0-32000 RPM
Overspeed trip range 100-32000 RPM
Acceleration trip range 0-25000 RPM/s
Working temperature -40 ° C to+85 ° C
Input power supply 18-32 Vdc
Analog input 4-20 mA, 7 channels configurable