WOODWARD 5466-258

Product Overview
The WOODWARD 5466-258 is a high-reliability digital speed sensing and protection module designed for prime mover control applications. Part of Woodward’s ProTech series, this microprocessor-based overspeed prevention device provides independent, third-layer protection for steam turbines, gas turbines, and critical rotating machinery. The WOODWARD 5466-258 operates completely independently of the primary control system, delivering failsafe shutdown capability when hazardous overspeed conditions are detected.

Technical Specifications
The WOODWARD 5466-258 accepts up to three magnetic pickup or proximity sensor inputs with frequency ranges from 1 Hz to 15 kHz. Each channel provides galvanic isolation and incorporates programmable setpoints for overspeed, underspeed, and rate-of-change detection. The module features six redundant relay outputs rated 10 A at 250 VAC/30 VDC with forced-guided contacts for positive position indication. The WOODWARD 5466-258 includes a front-panel backlit LCD display showing actual speed, setpoints, and trip history with time stamping. Power requirement is 18-32 VDC with 12 W maximum consumption. Housed in a rugged metal enclosure measuring 144 mm x 144 mm x 200 mm, the unit meets IP54 ingress protection and operates from -20°C to +70°C.

Key Features and Advantages

• Voting Logic Flexibility: The WOODWARD 5466-258 supports 1oo1, 1oo2, and 2oo3 voting configurations for nuisance trip avoidance while maintaining required safety integrity levels.

• Independent Operation: Utilizes separate speed sensors from the primary governor, eliminating common cause failure modes in overspeed protection chains.

• Sequence of Events Recording: Non-volatile memory stores last 50 trip events with 1 ms resolution for post-incident analysis.

• Manual Trip Test: Front-panel pushbuttons enable periodic proof testing without requiring machinery shutdown or sensor disconnection.

• Configurable Trip Multiplier: Automatically reduces overspeed setpoint during startup and synchronization periods when transient overshoot is expected.

Application Areas
The WOODWARD 5466-258 is the specified overspeed protection device for numerous Elliott, Siemens, and MAN Diesel & Turbo compressor trains in LNG liquefaction facilities. A major Middle Eastern gas processing plant recently standardized on the WOODWARD 5466-258 across 36 centrifugal compressor strings following a third-party safety audit recommendation. The module is also widely deployed in steam turbine-driven generator sets in biomass power plants and geothermal facilities requiring SIL 2 or SIL 3 certified over-speed protection.

Competitive Comparison
Versus the Amot 4320 and Protech203, the WOODWARD 5466-258 offers superior input frequency range and supports magnetic pickups directly without external signal conditioners. Unlike many competitive overspeed devices that require proprietary handheld programmers, the WOODWARD 5466-258 features full front-panel configurability with password protection. Its 2oo3 voting capability with three discrete sensor inputs provides higher availability than dual-channel competitors while maintaining the same SIL 3 certification level.

Selection Guidelines and Precautions

• Verify that the WOODWARD 5466-258 input impedance matches your existing magnetic pickup specifications; 500 ohm and 2000 ohm versions are available.

• The WOODWARD 5466-258 requires Woodward 5466-259 display/communications module for remote monitoring interface; order both part numbers for SCADA integration.

• Ensure all three relay outputs in the WOODWARD 5466-258 are wired to separate trip initiators when operating in 2oo3 mode to preserve voting integrity.

• Perform proof testing of the WOODWARD 5466-258 at intervals not exceeding five years as specified in the SIL manual.

• Configure underspeed detection setpoints at least 10% below minimum operating speed to prevent nuisance trips during normal speed variations.

• Order the WOODWARD 5466-258 with optional conformal coating when installing in high-humidity or marine environments to extend service life.