Description

Key Technical Specifications

Processor Type: Digital Microprocessor (505/505E Architecture)
Discrete Inputs: 16 Total (4 Dedicated, 12 Programmable)
Analog Inputs: 6 Programmable (4-20 mA)
Analog Output: 0-10V DC (for actuator/valve drive)
Communication: RS-232 / RS-422 with Modbus Protocol
Display: 2-Line x 24-Character LCD
Input Voltage: +24 Vdc @ 1 A
Operating Temp: -4°F to +140°F (-20°C to +60°C)
Storage Temp: -40°F to +185°F
Humidity: 95% RH (Non-condensing)
Enclosure Rating: IP56 (Front Panel)
Standard Functions: Critical Speed Avoidance, Auto-Start, Valve Limiting

Product Introduction

Steam turbines don’t forgive sloppy control logic, and mechanical governors are long gone. The WOODWARD 9907-164 is the digital brain that replaces them, sitting in the 505/505E series as a dedicated microprocessor controller for steam turbines, turbo-generators, and expander modules. It takes raw sensor data and executes complex PID loops for speed, load, and synchronization right at the panel, handling single extraction or admission valve control without waiting on a distant DCS.

Bottom line—this module keeps your prime mover stable when the grid gets messy. The WOODWARD 9907-164 features 16 discrete inputs and 6 programmable analog inputs, giving you enough I/O to handle permissives, limits, and process variables without adding extra cards. With built-in critical speed avoidance and auto-start sequencing, it prevents operators from accidentally driving the turbine through a mechanical resonance zone. You’re buying this because your turbine needs deterministic, local control that doesn’t rely on network latency.

Troubleshooting Quick Reference

Fault: Turbine hunts or speed oscillates
- Cause: PID gain too high or actuator hysteresis (70% probability)
- Relevancy: ✅ High
- Quick Check: Review PID parameters in the 505 menu. Check actuator linkage for binding.
- Fix: Reduce proportional gain. Verify actuator feedback matches valve position.
Fault: Display blank or module unresponsive
- Cause: 24V DC power loss or internal fuse (85% probability)
- Relevancy: ✅ High
- Quick Check: Measure +24 Vdc at the module input terminals. Check backplane fuses.
- Fix: Restore power. If voltage is present but module is dead, replace the WOODWARD 9907-164.
Fault: Modbus communication timeout
- Cause: Baud rate mismatch or wiring error (60% probability)
- Relevancy: ⚠️ Medium
- Quick Check: Verify DIP switch settings for baud rate. Check RS-232/422 wiring polarity.
- Fix: Correct wiring. Ensure master/slave configuration matches.

WOODWARD 9907-164

Application Scenarios & Pain Points

Steam Turbine Generators: Power plants need precise synchronization to the grid. The WOODWARD 9907-164 handles isochronous load sharing and droop control locally, ensuring the generator doesn’t trip offline during grid frequency dips.
Industrial Expanders: Gas processing plants use expanders for refrigeration. This module controls inlet guide vanes and speed to maintain process pressure, preventing liquid carryover that could destroy the expander wheel.
Mechanical Drive Turbines: Compressor stations rely on steam turbines for shaft power. The WOODWARD 9907-164 provides critical speed avoidance, automatically ramping through resonance zones during startup to prevent catastrophic shaft vibration.