Description
ℹ️ Product Overview & Datasheet Parameters
The Woodward DSLC Model 9905-373 is a microprocessor-based Digital Synchronizer and Load Control module designed for AC generators. Below are the ten core specification parameters detailing its build, origin, and technical ratings:
- Brand: WOODWARD
- Model Number: 9905-373
- Series: DSLC Digital Synchronizer and Load Control
- Product Name: Digital Synchronizer and Load Controller
- Place of Production: United States / Global Facilities
- Condition State: Brand New / Factory Recertified Options Available
- Dimensions: Standard Industrial Panel-Mount Form Factor
- Weight: Approx. 3.12 kg (6.88 lbs)
- Country of Origin: USA
- Power & Input Ratings: 120 Voltage Input, Open Delta PT Configuration, 500 Hz PWM Speed Bias Output
⚙️ Operating Guidelines & Usage Methods
Proper integration of the Woodward 9905-373 controller requires strict adherence to industrial electrical standards and precise wiring of open delta potential transformers (PTs) and current transformers (CTs) for accurate power monitoring. Operators must ensure that all control and measurement wiring utilizes shielded twisted-pair cables to mitigate electromagnetic interference (EMI) from adjacent high-voltage lines. Grounding must be implemented strictly in accordance with manufacturer guidelines to protect internal circuitry from ground loops and voltage transients. Configuration and parameter mapping can be handled using setup software or via connection interfaces mapped across the unit.
During active operation, continuous monitoring of three-phase true RMS power, voltage matching parameters, and synchronizer feedback is vital. Maintenance personnel should periodically inspect terminal block connections and verify that ambient operating temperatures remain within the specified industrial range of −40 to +70 °C. Never attempt internal component repairs or adjustments while the unit is energized, as this can cause permanent electrical damage or severe personal injury.
⚡ Power-Up & Power-Down Sequence
Industrial control hardware demands a structured sequencing protocol to prevent voltage spikes, data corruption, and out-of-phase breaker closure across parallel systems.
Startup Sequence:
- Verify that all external emergency stop circuits, safety interlocks, and auxiliary sensing lines are fully functional and in their normal standby states.
- Energize the auxiliary control power distribution panel, ensuring the input supply voltage stabilizes within its operational window.
- Allow the module internal boot sequence and diagnostic self-test to complete fully, observing the status indicators and front-face layouts.
- Bring the incoming generator up to rated speed and voltage, feeding the 120 voltage input open delta PT configuration correctly.
- Enable the synchronizer control loops to monitor bus and generator parameters, slip frequency, and voltage matching before permitting automated breaker closure.
Shutdown Sequence:
- Command an orderly unloading cycle via the controller interface to ramp active electrical load down to zero or minimum base load.
- Open the main generator circuit breaker once the unit is safely unloaded.
- Command the prime mover shutdown sequence, allowing engine or turbine deceleration to a complete standstill.
- De-energize the module input power supply and potential/current transformer feeds by opening the main control circuit breakers.
- Lock out and tag out (LOTO) all power sources if physical maintenance or module replacement is required.
📖 Product Operating Instructions
The Woodward 9905-373 operates by utilizing three-phase true RMS power sensing to deliver accurate measurements even under voltage fluctuations and unbalanced phase loading. It provides comprehensive features including synchronizing, dead bus closing, base loading, and isochronous load sharing across parallel AC generator applications. Unlike models utilizing standard DC voltage biases, this specific unit interfaces with compatible electronic governors or actuators using a 500 Hz PWM (Pulse Width Modulation) speed bias output signal. Operators interact with the unit using configuration software tools to set parameters, review event logs, and calibrate dynamic response loops.
❓ Frequently Asked Questions (Q&A)
Q1: What type of speed bias output does the 9905-373 model utilize? A1: This variant features a 500 Hz PWM (Pulse Width Modulation) speed bias output signal to communicate with and govern the prime mover’s speed control device.
Q2: What are the primary input specifications for this unit? A2: The module operates with a 120 voltage input rating and utilizes an open delta PT configuration for measuring and synchronization.
Q3: How does the unit maintain measurement accuracy during electrical disturbances? A3: It incorporates three-phase true RMS power sensing, ensuring precise calculations and reliable performance even during voltage fluctuations and unbalanced phase loading.
Q4: What environmental and temperature limits apply to this module? A4: The unit is rated for an industrial operating temperature range of −40 to +70 °C (−40 to 158 °F) and requires installation within a properly rated protective electrical enclosure to prevent moisture condensation.


