Woodward 2301A Modules 9905-068 2301A Load Sharing & Speed Controller

Technical Dossier

Product Details And Specifications

Woodward 2301A Series Technical Notes

The Woodward 2301A series represents one of the most widely deployed speed and load control platforms in global heavy industry. Installed across petrochemical refineries, nuclear power auxiliary systems, offshore platforms, and combined-cycle power plants, the 2301A architecture has maintained a dominant position in turbine governor and load-sharing applications for decades. Its modular analog and digital control topology made it the de facto standard for steam and gas turbine isochronous speed control in facilities where reliability over a 20–30 year asset lifecycle is non-negotiable. Units such as the 9905-068 2301A remain in active service across hundreds of installations globally, making long-term spare parts availability a critical operational concern for plant engineers and maintenance managers.

The Evolution of 2301A Architecture

The Woodward 2301A was introduced as a successor to the original 2301 analog governor platform, incorporating improved load-sharing bus communication and enhanced isochronous control algorithms. Early variants operated on a purely analog signal chain with 4–20 mA actuator outputs and discrete speed pickup inputs (magnetic pickup, MPU). Mid-generation revisions introduced improved EMI shielding and expanded droop/isochronous switching logic to support parallel generator sets and utility tie-line applications.

The 2301A series was later complemented by the 2301D (digital display variant) and eventually succeeded by the 2301E and EG-3P platforms, which introduced CAN-bus communication and configurable PID parameters via PC-based tooling. However, the 2301A remains in production support status, and its installed base is large enough that OEM-equivalent replacement modules and tested surplus units continue to be sourced through specialist distributors. Compatibility between sub-variants requires careful cross-referencing of part numbers, as hardware revisions altered terminal assignments and actuator driver impedance specifications.

2301A Full Catalog & Functionalities (SKU List)

The following SKUs represent the core and extended 2301A product family. Each unit is listed with its primary functional role as defined by Woodward's industrial control documentation:

9905-068 2301A: Load sharing and isochronous speed controller module, primary governor card for parallel gen-set applications.
9905-069 2301A: Speed controller module with droop mode, single-unit turbine governor variant.
9905-070 2301A: Load sharing module with analog load sensor input, utility parallel operation.
9905-148 2301A: Enhanced 2301A with extended temperature range, offshore/marine certified variant.
9905-149 2301A: Load sharing controller with dual MPU input redundancy.
9905-150 2301A: Speed/load controller with 4–20 mA remote setpoint input interface.
9905-151 2301A: Isochronous load sharing module, multi-unit bus configuration support.
9905-152 2301A: 2301A base module with integrated actuator driver, 100 mA output.
9905-153 2301A: Speed controller with configurable droop percentage, 0–10% range.
9905-154 2301A: Load sharing module with analog frequency reference input.
9905-155 2301A: 2301A variant with enhanced surge protection for high-noise environments.
9905-156 2301A: Dual-channel speed pickup input module, redundant MPU configuration.
9905-157 2301A: Load sharing controller with digital speed reference output.
9905-158 2301A: 2301A module with expanded I/O terminal block, 24 VDC logic supply.
9905-159 2301A: Speed and load controller, panel-mount DIN rail variant with conformal coating.
9905-160 2301A: 2301A with integrated overspeed test function and latching relay output.
9905-161 2301A: Load sharing bus master module for multi-generator isochronous systems.

Quality Control for the 2301A Range

The 2301A series presents specific test challenges due to its analog signal chain architecture and load-sharing bus communication protocol. DriveKNMS applies the following test procedures to all 2301A units prior to shipment:

Speed Pickup Signal Simulation: Each unit is tested with a calibrated MPU signal generator across the full operating frequency range (100 Hz – 10 kHz) to verify speed measurement accuracy and overspeed trip threshold calibration.
Actuator Output Load Test: The actuator driver output is tested under resistive load conditions matching standard Woodward EG and TM series actuator impedances to confirm current output linearity and stability.
Load Sharing Bus Verification: For load-sharing variants, the analog load-sharing bus interface is tested in a simulated multi-unit configuration to verify correct droop and isochronous mode switching behavior.
Power Supply Rejection Test: Input power supply ripple rejection is verified to confirm compliance with Woodward's specified 18–32 VDC operating range.
Thermal Burn-In: All units undergo a minimum 24-hour powered burn-in at elevated ambient temperature to screen for early-life component failures prior to release.