WOODWARD 8444-1067 Overspeed Protection Device

This model belongs to the Woodward ProTech-GII series and is a safety protection and overspeed detection device for prime movers (such as turbines and engines).

1. Product Description

The Woodward 8444-1067 is a ProTech-GII overspeed protection device. It is an independent meter or alarm module within the ProTech-GII series, designed to provide extremely reliable overspeed protection for rotating machinery.

It can monitor the signal from the speed sensor in real time and, upon detecting an overspeed condition exceeding the set value or a rapid change in rotational speed rate, promptly trigger the output relay to cut off the fuel or steam supply, preventing catastrophic accidents.

2. Technical Data Sheet

Model: 8444-1067

Series: ProTech-GII (Generation II)

Input power: Typically supports redundant power input (18–32 Vdc or a wider range, depending on the specific backplane).

Speed input: Supports 2 or 3 magnetic pick-up units (MPU) or proximity probes (Proximity Probe) inputs.

Response time: The response time for over-speed tripping is typically less than 20 milliseconds (ms).

Relay output: Equipped with safety trip relays (Trip Relays) and alarm relays (Alarm Relays).

Communication: Supports Modbus RTU serial communication, which is used for remote monitoring and diagnosis.

Protection level: The front panel typically reaches IP56 (when installed on the cabinet door).

Safety certification: Meets the SIL-3 safety integrity level requirements.

8444-1067

3. Related Models / Components

8444-1065 / 8444-1066: Different configuration versions of the ProTech-GII series.

8928-396: Specialized MPU speed sensor.

9907-018: A handheld programmer for parameter settings (although the GII series typically uses built-in buttons or software instead).

QuickTrip: Woodward Quick Release Block, usually used in conjunction with this module to perform the final shutdown operation.

4. Application Cases (Application Examples)

Steam Turbines: In power plants, they serve as the most crucial safety barrier, preventing the turbine from experiencing an overspeed explosion due to losing load.

Gas Turbines: Monitor rotor speed and provide final hard-wired protection in the event of failure of the fuel regulation system.

Centrifugal compressor: Protects the compressor unit from being damaged due to the loss of control of the drive unit.

Large ship engine: Monitors the rotational speed of the main engine of the ship to ensure safe operation in harsh sea conditions.

5. Product Advantages and Features (Product Features and Strengths)

High Integrity: The design complies with the SIL-3 standard and is suitable for applications with extremely high safety requirements.

Ultra-fast response: The sub-cycle detection algorithm ensures immediate response when the rotational speed just exceeds the limit, protecting the expensive rotating components.

Redundancy Architecture: Supports two-out-of-three (2-out-of-3) or one-out-of-two tripping logic, ensuring safety while significantly reducing the occurrence of misstops due to the failure of a single sensor.

Built-in testing function: Enables “online local disconnection testing” (Online Testing) during the machine’s operation without causing actual downtime.

Fault log: It can record the maximum rotational speed data at the moment of tripping, facilitating fault analysis after the incident.

6. Other Models in the Series

The safety protection series of Woodward also includes the following products:

ProTech-SX: Simplified version of protection device with single or dual channels.

ProTech TPS: Features a three-redundant version of the total trip system.

Peak 200: Turbine controller with both control and protection functions.

MicroNet TMR: A triple-redundant fault-tolerant control system suitable for the highest level of security requirements.