Description
The Woodward 9907-014 is a low-voltage electronic governor module belonging to the 2301A product series. Engineered for high-precision speed control and isochronous or droop load sharing, this module regulates diesel engines, gas engines, or steam turbines driving electrical generators or mechanical loads. Operating on a nominal 24 V DC input, the 9907-014 processes frequency inputs from a magnetic pickup (MPU) and drives a 0 to 200 mA analog output to position proportional fuel actuators.
Technical Specifications
| Parameter | Value |
| Model Number | 2301A Series |
| Part Number | 9907-014 |
| Manufacturer | Woodward |
| Input Power Requirements | 18 to 40 V DC (24 V DC Nominal); 15 W maximum power consumption |
| Speed Sensor Input | Magnetic Pickup (MPU), 1.0 to 30 V AC RMS |
| Actuator Output Current | 0 to 200 mA DC, suitable for standard Woodward proportional actuators |
| Operating Modes | Isochronous (constant speed) or Droop (speed varies with load) |
| Load Sharing Interface | 0 to ±3 V DC proportional load sharing lines for parallel operation |
| Operating Temperature | −40 to +70 °C (−40 to +158 °F) |
| Mounting Orientation | Chassis/Surface mounted via baseplate |
| Weight | Approximately 1.5 kg (3.3 lbs) |
Commercial and Logistics Information
- Condition: New Original (Factory Sealed Surplus) or Refurbished (Tested on Engine Simulators)
- Warranty: 12-month industrial-grade warranty from date of dispatch
- Availability: Standard stock item; typically processed and shipped within 1 to 2 business days
- Logistics: International priority shipping supported via DHL, FedEx, or UPS
- Pricing Policy: Indicative only. Prices fluctuate based on market availability and component lifecycle; contact us for a binding commercial quote.
Architectural and Operational Insights
Speed Control Dynamics and Adjustments
The 9907-014 uses an analog control loop to maintain precise prime mover shaft speeds. The governor features several built-in, multi-turn potentiometers accessible on the chassis faceplate to fine-tune loop stability:
- Gain: Adjusts the responsiveness of the governor to speed deviations (proportional band).
- Stability: Adjusts the reset rate (integral action) to eliminate steady-state speed errors without introducing hunting.
- Actuator Compensation: Matches the electronic output time constant to the mechanical inertia and fuel rack linkage response time of the specific engine or turbine.
Isochronous Load Sharing Network
When multiple generator sets operate in parallel on an isolated bus, the 9907-014 coordinates proportional load distribution through a dedicated parallel wiring scheme. By interconnecting the “Load Sharing Lines” (shielded twisted pair wires running peer-to-peer between each 2301A governor), the modules establish a common bias voltage. Each governor compares its internal generator current transformer (CT) input to this bias line, dynamically biasing its fuel rack command to force all running engines to carry an equal percentage of their rated electrical capacities.
Typical Interconnection Topology
[ Magnetic Pickup (MPU) ] ───(Speed Signal)───┐
▼
[ Generator CT / PT ] ─────(Load Signal)───► [ Woodward 9907-014 ] ───► [ Proportional Actuator ]
▲ (0 - 200 mA Fuel Control)
[ Adjacent 2301A Governor ] ◄──(Load Share Bus)─┘
Installation and Maintenance Field Notes
Fail-Safe Speed Signal Monitoring
The 9907-014 incorporates a critical MPU break-protection circuit. If the magnetic pickup signal drops to zero volts while the module is active (indicating a severed sensor cable or physical target misalignment), the governor instantly clamps the actuator output down to 0 mA. This action forces the proportional fuel valve or rack to its minimum fuel stop, protecting the prime mover from catastrophic overspeed conditions.
Shielding and Noise Mitigation Rules
Important Noise Mitigation Rule: Electrical noise on the low-level MPU or Load Sharing signal wires will cause erratic actuator positioning and generator load hunting. Always use high-quality shielded twisted-pair cabling for the magnetic pickup, actuator lines, and load sharing bus. Terminate the wire shields only at the governor end to an isolated chassis ground point. Do not ground the shields at both ends, as this will create a ground loop capable of inducing false speed pulses into the processor circuit.
Start Fuel Limit Configuration
To minimize exhaust smoke and structural thermal stress during startup, the module includes an adjustable Start Fuel Limit feature. This circuit clamps the maximum allowable actuator current during the initial cranking sequence. Once the engine catches and the MPU registers that the shaft speed has reached the predefined breakaway threshold, control transfers cleanly over to the primary speed control loop.
Frequently Asked Questions
What should I check if a parallel generator set is “hunting” or swinging load?
If a generator set cannot stabilize its load share configuration, check the following:
- Verify that the polarity of the Load Sharing Lines is uniform across all connected 2301A units (Terminal + to +, Terminal – to -).
- Ensure the generator’s phase-matched current transformer (CT) output is wired correctly and is not phase-shifted relative to the potential transformer (PT) voltage sensing inputs.
- Isolate the unit from the parallel bus and run it in standalone Isochronous mode. If it runs smoothly alone, the issue resides in the load lines or the CT scaling rather than the base engine stability settings (Gain/Stability).
Can I replace an older 2301 series governor with this 2301A model?
Yes, the 2301A series (including the 9907-014) is designed to replace most legacy, low-voltage 2301 variants. However, because terminal designations and physical terminal layouts differ between older generations and the modern 2301A chassis, you must map the terminal assignments carefully using the official cross-reference wiring diagram in the Woodward manual.
How do I calibrate the rated speed if the potentiometer runs out of range?
The on-board “Rated Speed” potentiometer provides a finite adjustment window around a base frequency. If you cannot reach your required synchronous speed (e.g., 1500 RPM for 50 Hz or 1800 RPM for 60 Hz), you may need to add or remove external resistance across the auxiliary speed trim terminals, or verify that the physical gear tooth count on the flywheel matches the input range specification of the 9907-014 hardware design.
