The Woodward 9905-387 ProAct Driver Model-III is a high-performance, microprocessor-based power amplifier designed to control ProAct digital electric actuators. This driver functions as the critical interface between an engine or turbine controller and the actuator, providing the precise electrical current necessary to position the fuel rack or throttle valve with exceptional speed and accuracy.

 

Product Overview

The Model-III ProAct Driver is engineered for large-bore engines and industrial turbines that require high-torque actuation. It accepts a variety of control signals and converts them into a high-current PWM (Pulse Width Modulation) output to drive the actuator motor. With its rugged construction and advanced thermal management, the 9905-387 ensures reliable operation in demanding engine room environments, offering enhanced diagnostics and programmable parameters to optimize linkage dynamics.

Technical Datasheet

General Specifications

• Product Name: Woodward ProAct Driver Model-III
• Part Number: 9905-387
• Driver Type: Digital Actuator Driver / Power Amplifier
• Input Voltage: 18–32 VDC (24V Nominal)
• Maximum Output Current: 30A (Peak) / 15A (Continuous)
• Control Input: 4–20 mA, 0–5 VDC, or PWM Command
• Feedback Signal: Integrated Position Feedback (0.5–4.5 VDC)
• Enclosure Rating: IP56 (when mounted correctly)
• Operating Temperature: -40°C to +70°C
• Dimensions: 225mm x 155mm x 85mm
• Weight: 2.45 kg
• Country of Origin: USA

 

Application Fields

• Gas Engine Control: Driving throttle valves on large reciprocating gas engines for power generation.
• Diesel Engine Governors: Fuel rack positioning for marine propulsion and industrial backup power.
• Steam Turbines: Controlling governor valves for precise speed and load management.
• Mechanical Drive Systems: Managing air-fuel ratio valves and large-scale process control actuators.

 

Product Instructions

• Mounting: Install the driver in a vertical orientation to maximize natural convection cooling. Avoid mounting directly on high-vibration engine components; use a remote bracket if necessary.
• Power Wiring: Use heavy-gauge wire (minimum 12 AWG) for the DC power input and actuator output leads to minimize voltage drop. Ensure the 24V source is capable of handling peak current surges.
• Configuration: The Woodward 9905-387 is configured using Woodward Watch Window or similar service tools. Adjust gain, stability, and dead-band settings to match the mechanical linkage of the engine.
• Grounding: Ensure a low-impedance chassis ground connection to reduce EMI and protect the internal microprocessor from electrical noise.

 

Q&A: Frequently Asked Questions

• Q: Can this driver be used with any actuator?
  • A: No, the 9905-387 Model-III is specifically designed to drive Woodward ProAct series actuators. Using it with other brands may damage the driver or the motor.
• Q: What does a flashing “Status” LED mean?
  • A: A flashing LED typically indicates a diagnostic fault, such as an actuator position error, input signal loss, or internal over-temperature condition.
• Q: Is a separate power supply required for the feedback sensor?
  • A: No, the driver provides a regulated 5V reference output specifically for the actuator’s internal position feedback sensor.
• Q: How does the “Fail-Safe” mode work?
  • A: In the event of a lost control signal or internal fault, the driver can be programmed to either hold the last position or drive the actuator to a pre-defined minimum fuel/shutdown position.

 

Recommended Similar Models

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