Woodward 9905-387 ProAct Digital Driver III and 2301D Speed Control Unit

The Woodward 9905-387, also cataloged as the 9905-387 Digital Speed Control Unit & ProAct Driver, serves as the primary 9905-387 Actuator Driver and Speed Governor utilized to execute precise electronic fuel metering and valve positioning across industrial turbine and engine platforms.

Hardware Specifications

Actuator Loop Feedback Response and Dynamic Control

The hardware features an integrated processing unit configured for V/Hz profiles and field-oriented digital control algorithms. It directly dictates the actuator loop feedback response by calculating discrete speed changes via high-frequency Magnetic Pickup Unit (MPU) inputs up to 10,000 RPM. The internal control logic executes parallel load sharing, isochronous balancing, and droop compensation loops. Thermal heat sink dissipation profiles are integrated into the heavy-duty chassis construction, maintaining steady gate-drive switching loops and preventing thermal drift under maximum inductive actuator loads.

Frequently Asked Questions

Q: What are the restrictions regarding the maximum physical cable length between the magnetic pickup sensor and the input terminals of this module?

A: To maintain proper speed loop feedback response and minimize harmonic distortion suppression errors, the MPU signal line must not exceed standard engineering limits and must use twisted-shielded instrumentation cables.

Q: Can the 9905-387 module be serviced or calibrated while the turbine speed control loop is active?

A: No. Altering internal control parameters via the serial link during operation will cause immediate step changes in the actuator output loop, risking severe mechanical overspeed faults or an immediate emergency trip.

Field Installation Guidelines

• Mount the control unit vertically inside a protective metal cabinet using the designated mounting hole layout to maximize convective air flow over the thermal heat sink.
• Route all 24 VDC power supply wires through separate conduits away from low-level magnetic pickup (MPU) lines and serial communication cables.
• Terminate all communication and feedback shields only at the specified system grounding bus bar to prevent ground loop noise from corrupting data.
• Ensure all terminal block terminal screws are torqued properly to maintain structural integrity under continuous engine vibration profiles.
• Configure the 4-20 mA feedback loop parameters using Woodward 505View or OpView software before completing the mechanical connection to the fuel valve actuator.