Product Description

Overview

The 9905-211 from Woodward is a precision Digital Speed and Load Control Module designed for reciprocating engines, including diesel and gas types. Part of the 701 Digital Speed Control series, it delivers stable engine performance under varying load conditions and integrates seamlessly with Woodward or compatible proportional actuators. This model is optimized for high-voltage applications (90–150 VDC or 88–132 VAC) and is suitable for bulkhead or panel mounting in generator sets and industrial drive systems.

Core Functional Features

Dual-Mode Speed Regulation

• Isochronous Operation: Maintains constant engine speed regardless of load fluctuations, ensuring stable frequency output for power generation.

• Droop Operation: Allows speed to decrease proportionally with load, ideal for parallel generator operation or connection to an infinite bus.

Load Sharing Capability

• Proportional load-sharing ensures multiple generators evenly distribute the total electrical load according to individual capacity, preventing overloading of any single unit.

Actuator Interface

• Provides 0–200 mA DC output to proportional actuators, automatically adjusting based on the difference between setpoint and feedback signals.

Automatic Protection & Monitoring

• Includes fail-safe circuitry to shut down the actuator if the Magnetic Pickup (MPU) signal is lost, preventing overspeed conditions.

• User-adjustable potentiometers allow tuning for Gain, Reset, and Actuator Compensation to optimize engine response and minimize hunting.

Environmental Resilience

• Rugged chassis designed to withstand vibration, EMI, and industrial operating conditions.

• Operating temperature: -40°C to +70°C.

Technical Specifications

Applications

• Generator sets requiring precise speed control and load sharing.

• Industrial engines used in mechanical drives, cogeneration, or backup power systems.

• Integration with Woodward actuators for responsive engine management.

FAQ

Q: Can the 9905-211 interface with non-Woodward actuators?
A: Yes, as long as the actuator accepts proportional 0–200 mA control input.

Q: What happens if the Magnetic Pickup signal is lost?
A: The fail-safe circuit shuts down the actuator automatically to prevent overspeed.

Q: Is it suitable for high-vibration environments?
A: Yes, the module is designed for heavy vibration and EMI typical of engine rooms.