Woodward Safety Systems
Safety Systems for Industrial Applications
ProTech®-GII Overspeed Protection Device
Woodward’s ProTech®-GII is an overspeed safety device designed to safely shut down steam, gas, and hydro turbines upon sensing an overspeed or over acceleration event. This device accurately monitors turbine rotor speed and acceleration via active or passive MPUs (magnetic pickups) and issues a shutdown command to the turbine’s trip valve(s) or corresponding trip system.
- The ProTech-GII is IEC61508 SIL-3 Certified and API670 & API612 Compliant.
Learn more from the ProTech-GII product specification
- Optionally the ProTech-GII can be configured to protect a turbine from high acceleration events also. The derivative of the speed signal is used to detect turbine acceleration and issue an associated trip command.
- Each module’s speed sensor input uses special MPU open-wire detection circuitry to validate that the MPU is properly connected before turbine operation, and special loss-of-speed detection logic to validate MPU functionality during turbine operation.
Automatic Overspeed Test Routine
- Optionally the ProTech-GII can be configured to routinely perform an overspeed test of each module, then log and report the test results. With this test routine, each module goes through its test sequence using an internal frequency generator to simulate an overspeed condition.
Sulfur Contamination Resistant
- The ProTech-GII utilizes a special conformal coating material that has demonstrated excellent long-term protection against H2S and SO2 gases at levels classified in international standard IEC 721-3-3 1994 - environment Class 3C2.
- The ProTech-GII’s triple-modular design allows users to easily replace one of its modules (A, B, C) while the turbine is on-line and operating normally. Ease of replacement is enhanced by the unit’s backplane plug-and-operate structure, and its module-to-module learning function.
This fast acting overspeed protection device is designed to be applied in conjunction with a turbine control or trip system to safely shut down the turbine in the case of a turbine overspeed event. Interface with related control systems or plant DCS(s) (Distributed Control Systems) can be performed via the ProTech-GII’s redundant hard-wired input and output signals or through its triple-redundant serial Modbus communications ports.
- Each ProTech-GII module can be tested manually from the module’s front panel, Modbus communications port, or automatically via its auto-test routine function. The ProTech-GII allows users to configure an overspeed test to be performed automatically on a periodic basis, testing each module (A, B, C) one at a time, and logging the result of each test or halting the test for a sensed error.
Trip, Alarm, & Overspeed Logs
- The ProTech-GII log function logs (saves to memory) all trips, alarms, trip valve response times, and overspeed events. The trip-log function uses a scrolling buffer and records the last 50 sensed trip or alarm events and the last 20 overspeed events to memory, with associated times. Each log file can be viewed from the unit’s front panel, or downloaded to a computer via the ProTech-GII service tool program. Each module utilizes non-volatile memory to ensure that all logged events are saved, even on loss of power.
Real Time Clock
- Each ProTech-GII module utilizes a real-time clock to ensure accurate time logging. A special timeaveraging function is utilized between modules to to ensure module-to-module clock synchronization.
North American Compliance:
- CSA Certified for Class I, Division 2, Groups A, B, C, and D, T3 at 60 °C Ambient for use in Canada and the United States
- EMC Directive: 2004/108/EC
- ATEX Directive:94/9/EC Zone 2, Category 3, Group II G, Ex nA II T3
Other International Compliance:
- TÜV certified for SIL-3 per IEC 61508 Parts 1-7, Function Safety of Electrical / Electronic / Programmable Electronic
- Safety Related Systems
- IEC60068-2-60:1995 Part 2.60 Methods 1 and 4 (conformal coating)API670 & API612 compliant
- RoHS Exempt per Annex IA of Directive 2002/96/EC referring to "monitoring and control instruments" within the meaning of Category 9