Description
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- The Woodward 9905-971 is a sophisticated microprocessor-based controller designed for the operation and protection of single-extraction or admission steam turbines. As part of the highly reliable 505 series, this unit provides comprehensive governing, including speed control, load management, and auxiliary pressure or process control. Its field-programmable nature allows it to be adapted to a wide variety of turbine applications, ensuring maximum efficiency and operational safety.
Product Specifications
- Model Number: 9905-971
- Manufacturer: Woodward
- Control Type: Digital Steam Turbine Controller (505 Series)
- Input Voltage: 18–32 VDC
- Speed Sensing: Dual Magnetic Pickup (MPU) or Proximity Probe inputs
- Actuator Outputs: 4–20 mA or 20–160 mA configurable signals
- Communication: RS-232, RS-422, or RS-485 Modbus RTU ports
- Display: Integrated Vacuum Fluorescent Display (VFD) with 2 rows of 20 characters
- Operating Temperature: -25°C to +65°C
- Dimensions: 483mm x 177mm x 103mm (Standard Rack Mount)
- Weight: 3.6 kg (7.94 lbs)
- Country of Origin: USA
Application Fields
This controller is the industry standard for managing steam turbine dynamics in critical sectors:
- Industrial power plants for generator frequency regulation.
- Combined Cycle Power Plants (CCPP) for waste heat recovery turbines.
- Paper and pulp mills for mechanical drive turbines (fans, pumps, and compressors).
- Sugar refineries and chemical plants utilizing process steam for mechanical power.
Usage Instructions
When commissioning the Woodward 9905-971, ensure the unit is mounted in a location that permits easy access to the front panel keypad for configuration. Start by defining the turbine’s physical parameters, including the number of teeth on the speed gear and the minimum/maximum valve positions. The 505 series uses a menu-driven interface to walk the user through “Configure Mode” for I/O mapping and “Service Mode” for PID tuning. During initial startup, use the “Inching” function to verify actuator movement before introducing steam. All wiring should use shielded, twisted-pair cables to protect against electromagnetic interference (EMI).
Frequently Asked Questions (Q&A)
Q: Can the 9905-971 handle automatic generator synchronization? A: Yes, it includes internal logic for speed matching and frequency synchronization, which can be interfaced with an external automatic synchronizer or controlled manually through the keypad.
Q: What is the benefit of the dual MPU inputs? A: Redundancy. If one speed sensor fails, the controller can automatically switch to the second signal, preventing a nuisance trip and allowing for continuous, safe operation.
Q: How do I backup the configuration settings? A: You can use Woodward’s Watch Window or specialized PC tools to upload the configuration file from the 9905-971 and save it as a backup on a laptop for future restoration.
Related Model Recommendations
- Woodward 9907-164 (505E Digital Control)
- Woodward 8200-1302 (Peak 150 Controller)
- Woodward 9905-020 (MicroNet CPU)
- Woodward 8272-466 (2301A Load Sharing)
- Woodward 5466-1035 (MicroNet P1020 CPU)
- The Woodward 9905-971 is a sophisticated microprocessor-based controller designed for the operation and protection of single-extraction or admission steam turbines. As part of the highly reliable 505 series, this unit provides comprehensive governing, including speed control, load management, and auxiliary pressure or process control. Its field-programmable nature allows it to be adapted to a wide variety of turbine applications, ensuring maximum efficiency and operational safety.
