Description BL20-400 Woodward ProTech-GII Overspeed Protection Device Product Dimensions： Product Description (Detailed Explanation) The ProTech-GII is an advanced safety PLC specifically dedicated to speed monitoring. It is designed to replace mechanical trip bolts and older electronic trip systems. Triple Modular Redundancy (TMR): The ProTech-GII (specifically models like the BL20-400) often utilizes a “two-out-of-three” (2oo3) voting logic. It contains three independent monitoring channels; if any two channels detect an overspeed condition, the system initiates a trip. Speed Sensing: It picks up magnetic pickup (MPU) or proximity probe signals to calculate the exact RPM of the shaft. Integrated Safety: It is designed to be SIL-3 (Safety Integrity Level 3) capable, ensuring that it will perform its safety function even in the event of internal component failures. Product Parameters (Technical Specifications) Parameter Category Specification Input Channels 3 Independent Speed Inputs (MPU or Eddy Current) Logic Configuration 2-out-of-3 (2oo3) Voting Response Time < 12 milliseconds (Total system response to trip) Power Supply Dual Redundant Inputs (High Voltage 88–264 Vac / 90–150 Vdc or Low Voltage 18–32 Vdc) Relay Outputs Configurable Trip and Alarm Relays Communication Modbus TCP/UDP or Modbus RTU (for diagnostics) Enclosure Rating IP56 (when installed in appropriate housing) Frequency Range 0.5 Hz to 25,000 Hz Product Advantages (Key Benefits) Extremely Fast Response: At less than 12ms, it is significantly faster than standard PLCs, which is vital for preventing turbine “runaway” scenarios. High Availability: Because of the 2oo3 voting logic, a single sensor failure or a single internal module failure will not cause a “nuisance trip,” keeping the machine running while allowing for repairs. Internal Diagnostics: The device continuously performs “self-tests.” It can detect failed sensors, open circuits, or internal logic errors and alert the operator immediately. Peak Speed Capture: It automatically records the highest speed reached during an event, which is essential for post-trip analysis and insurance documentation. On-Line Testing: Operators can test individual channels of the trip system while the turbine is still running without risking an actual machine shutdown. Precautions (Important Notes) Magnetic Pickup (MPU) Alignment: Ensure the speed sensors are gapped correctly according to the turbine manufacturer’s specs. A weak signal can lead to “Loss of Speed” alarms. Wiring Separation: Speed sensor cables must be shielded and routed away from high-voltage power cables to prevent electromagnetic interference (EMI) from causing false speed readings. Configuration Locking: Once the trip setpoints are commissioned, the device should be password-protected or physically locked to prevent unauthorized changes to safety parameters. Relay Protection: When connecting the trip relays to heavy-duty solenoids, ensure appropriate snubbers or diodes are used to protect the ProTech-GII contacts from inductive flyback. Product Applications (Typical Use Cases) The BL20-400 is found in high-stakes energy and industrial environments: Steam Turbines: Providing primary and emergency overspeed protection in nuclear, coal, and combined-cycle power plants. Gas Turbines: Monitoring the high-speed shafts of industrial gas turbines used for power generation or mechanical drive. Hydroelectric Turbines: Protecting large-diameter, high-inertia water turbines from overspeeding during load rejection. Critical Pumps/Compressors: Ensuring that large steam-turbine-driven compressors in refineries do not exceed their mechanical speed limits. Shipping Port: Xiamen, China Payment: Bank of Chicago, Bank of Singapore Express cooperation: fedex, DHL, UPS and your express account Service: Professional Sales provides 24 hours /7 days online service Please make an inquiry for more models： 5501-381 WOODWARD 5466-1047 WOODWARD 8200-226 WOODWARD 5466-1049 WOODWARD 8250-565 WOODWARD 5466-253 WOODWARD 8272-582 WOODWARD 5501-365 WOODWARD 8290-189 WOODWARD 723PLUS WOODWARD 8290-191 WOODWARD 8200-203 WOODWARD 8290-195 WOODWARD 8235-622 WOODWARD 8405-307 WOODWARD 8251-766 WOODWARD 8406-113 WOODWARD 8405-011 WOODWARD 8407-522 WOODWARD 8405-084 WOODWARD 8440-1706 WOODWARD 9904-041 WOODWARD 8440-1831 WOODWARD 9905-028 WOODWARD PCU-DPIO V4.6.3 WOODWARD 9905-392 WOODWARD 1680-2004 WOODWARD 9905-463 WOODWARD 8235-154 WOODWARD 9905-792 WOODWARD 8250-573 WOODWARD 9905-990 WOODWARD 8273-140 WOODWARD 9907-1106 WOODWARD 8440-2165 WOODWARD 9907-186 WOODWARD 8901-457 WOODWARD 9907-205 WOODWARD 8923-1633 WOODWARD 9907-345 WOODWARD