Woodward 9905-976 Overspeed Protection System

Description

The 9905-976 system is a high-reliability overspeed protection device designed for critical rotating machinery. It reads three individual magnetic pickups (MPUs) and performs three separate speed calculations. Using a two-out-of-three hardware voting mechanism, it ensures accurate overspeed detection and protection, minimizing false trips and ensuring system safety.

Specifications

• Dimensions: 482.6 x 310.4 x 142.7 mm
• Weight: Less than 15 lbs
• Input Voltage: 88-132 VAC, 90-150 VDC
• Keypad/Display: 1 Keypad and Display per Module
• Operating Temperature: -25°C to +60°C
• Response Time: Max 40 ms from speed sampling to trip relay activation
• Trip Speed Set Point: 250 rpm minimum, 25,000 rpm maximum
• MPU Fail Set Point: 100 rpm minimum, 25,000 rpm maximum

Features

• Three Independent Speed Calculations: Enhances reliability and precision by cross-verifying speed data from three separate sensors.
• Modular Design: Reduces downtime with easy module replacement and redundant system configuration.
• Energize-to-Trip Model: Triggers a trip relay to shut down the system if overspeed conditions are met.
• Tunable Parameters: Adjustable trip speed set point, MPU fail set point, and optional trip on MPU failure for customized protection.