Woodward 8237-1597 ProTech-GII Overspeed Protection Controller

Overview

The 8237-1597 overspeed protection unit from Woodward’s ProTech-GII platform is an independent safety controller engineered to protect high-speed rotating equipment from destructive overspeed events. Designed for critical turbomachinery, it continuously monitors shaft speed and initiates decisive trip actions when predefined safety thresholds are exceeded. The ProTech-GII architecture advances beyond earlier generations by combining fault tolerance, fast response, and comprehensive self-monitoring in a single enclosure.

System Architecture and Operating Principle

The controller employs a Triple Modular Redundancy design with a 2-out-of-3 voting scheme. Three autonomous processing channels evaluate speed data simultaneously; a shutdown command is issued only when at least two channels agree that an unsafe condition exists. This approach minimizes nuisance trips while maintaining strict protection integrity suitable for SIL-rated turbine applications.

Key Technical Characteristics

• Redundant TMR processing with continuous cross-channel diagnostics
• High-resolution speed acquisition suitable for rapid acceleration detection
• Deterministic response for emergency trip initiation
• Modular internal design allowing channel-level servicing without full system replacement

Electrical and Environmental Specifications

• Supply options: 12 VDC or 24 VDC
• Internal logic/output reference voltage: 5 VDC
• Maximum output current capability: up to 10 A (relay dependent)
• Typical power dissipation: approximately 25 W
• Operating temperature range: –20 °C to +85 °C
• Enclosure protection: IP56, suitable for turbine hall environments

Speed Measurement Performance

• Supported speed range: 0 to 10,000 RPM
• Measurement accuracy: ±0.1% of reading
• Sampling frequency: 1 kHz for high-speed transient detection

Input and Output Interfaces

• Speed signal inputs: 4–20 mA compatible speed transmitters
• Discrete voltage inputs:
  • Low-level DC: 18–32 VDC
  • High-level DC: 100–150 VDC
• Outputs:
  • Safety-rated relay contacts for trip and shutdown circuits
  • Digital status outputs for alarms and system health indication

Integrated Functions

• Primary and secondary overspeed protection
• Emergency trip and shutdown logic
• Online speed test and proof-testing support
• Event logging and fault history capture
• Automatic self-diagnostics with channel fault isolation

Typical Applications

• Gas and steam turbine overspeed protection systems
• Hydro turbine mechanical protection
• High-speed diesel engines
• Generator drive trains and critical rotating machinery

Frequently Asked Questions

What distinguishes ProTech-GII from earlier ProTech models?
ProTech-GII introduces enhanced diagnostics, improved processing performance, and a more serviceable modular architecture while maintaining true TMR safety integrity.

Can the 8237-1597 operate as a standalone safety device?
Yes. It is designed to function independently of the main control system, ensuring overspeed protection even if the primary control PLC or DCS fails.

Is this controller suitable for continuous operation in harsh environments?
The IP56 enclosure and extended temperature range make it appropriate for long-term use in turbine enclosures and power generation facilities.