The Woodward 9905-462 is a high-performance digital governor system designed for precise speed and load control of industrial turbines, generators, and other prime movers. Part of Woodward's EasyGen 3000XT series, this controller offers advanced functionality in a compact, rugged package suitable for harsh industrial environments.

This microprocessor-based controller provides exceptional control accuracy and reliability, making it ideal for critical applications in power generation, oil and gas, marine, and industrial process automation.

Input Signals

• Speed reference: 4-20 mA or 1-5 VDC
• Speed feedback: Magnetic pickup (MPU) or proximity sensor
• Load feedback: 4-20 mA (optional)
• Digital inputs: 8 optically isolated inputs

Output Signals

• Actuator output: 4-20 mA
• PWM output for hydraulic actuators
• Digital outputs: 4 relay outputs (Form C)
• RS485 communication port (Modbus RTU)

Controller Unit (CU)

The main processing unit that implements the control algorithms and logic. It receives input signals, processes them according to the selected control mode, and generates output signals to the actuator.

Key components:

• Microprocessor with floating-point unit
• Non-volatile memory for configuration
• Real-time clock for time-stamping events
• Watchdog timer for fault detection

Sensor Interface (SI)

Provides signal conditioning and isolation for the input sensors. It processes signals from speed sensors, position sensors, and other feedback devices.

Key features:

• Signal conditioning for various sensor types
• Galvanic isolation between sensors and controller
• Filtering to reduce noise interference
• Sensor fault detection and diagnostics

Actuator Module (AM)

Converts the controller's output signals into appropriate commands for the actuator. It provides power amplification and drive circuitry.

Supported actuators:

• Hydraulic actuators (via I/H converter)
• Electric actuators (DC motor drives)
• Pneumatic actuators (via I/P converter)
• Proportional solenoid valves

4.1 Mounting Instructions

1. Mounting Location: Select a location that is protected from excessive heat, vibration, moisture, and electromagnetic interference. The controller should be mounted in a vertical position with adequate ventilation.
2. Mounting Hardware: Use M5 screws (not provided) to mount the controller to a flat surface. Torque the screws to 1.5 Nm (13 in-lb).
3. Clearance Requirements: Maintain a minimum clearance of 50 mm (2 inches) around the controller for proper ventilation.
4. Shock and Vibration: The controller is designed to withstand shock and vibration up to 20 g (10 ms) and 10 g (5-2000 Hz), respectively. For environments with higher levels, additional mounting isolation may be required.

4.2 Wiring Instructions

1. Power Wiring: Connect the power supply to the terminal block marked "POWER". Observe proper polarity (positive and negative).
2. Sensor Wiring: Connect the speed sensor to the terminal block marked "SENSOR". Follow the wiring diagram for proper connections.
3. Actuator Wiring: Connect the actuator to the terminal block marked "ACTUATOR". Ensure proper wire gauge for the current requirements.
4. Control Signals: Connect external control signals (4-20 mA or 1-5 VDC) to the terminal block marked "CONTROL INPUTS".
5. Communication Wiring: If using the RS485 communication port, use twisted-pair shielded cable. Connect the shield to the ground terminal at one end only.
6. Wire Gauge: Use 16-22 AWG wire for all connections. For power connections, use 16 AWG wire.
7. Torque Specifications: Torque all terminal block screws to 0.5 Nm (4.4 in-lb).

4.3 Terminal Block Assignments

5.1 Parameter Configuration

The Woodward 9905-462 controller can be configured using the front panel keypad and display, or via a PC using the Woodward Configuration Software (WCS) and the RS485 communication port.

5.1.1 Front Panel Configuration

1. Enter Configuration Mode: Press and hold the "CONFIG" button for 3 seconds until the display shows "CONFIG MODE".
2. Navigate Parameters: Use the "UP" and "DOWN" arrow buttons to navigate through the parameter menu.
3. Select Parameter: Press the "ENTER" button to select a parameter for editing.
4. Edit Parameter: Use the "UP" and "DOWN" arrow buttons to change the parameter value. Press "ENTER" to save the new value.
5. Exit Configuration Mode: Press and hold the "CONFIG" button for 3 seconds until the display returns to normal operation.

5.1.2 PC Configuration

1. Install Software: Install the Woodward Configuration Software (WCS) on your PC.
2. Connect PC to Controller: Connect the PC to the controller using an RS485-to-USB converter.
3. Launch Software: Start the WCS and establish communication with the controller.
4. Read Configuration: Click the "Read" button to upload the current configuration from the controller.
5. Modify Parameters: Edit the parameters as needed using the software interface.
6. Write Configuration: Click the "Write" button to download the modified configuration to the controller.

5.2 Control Modes

The Woodward 9905-462 controller supports two main control modes:

5.4 Key Parameters

6.1 Fault Codes

The Woodward 9905-462 controller provides diagnostic information through fault codes displayed on the front panel. When a fault occurs, the red FAULT LED illuminates, and the fault code is displayed.

6.2 Common Issues and Solutions

6.3 Diagnostic Tools