Description
Product Datasheet & Technical Parameters
- Brand: WOODWARD
- Model: 9905-709
- Series: DSLC (Digital Synchronizer and Load Control) Series
- Product Name: Digital Synchronizer and Load Control Unit
- Manufacturing Origin: United States
- Physical Condition: Brand New / Factory Sealed
- Dimensions: 18.14 in \times 10.4 in \times 2.3 in (461 mm \times 265 mm \times 59 mm)
- Weight: Approx. 6 lbs 14 oz (3.12 kg)
- Country of Origin: USA
- Power / Input Rating: 240 VAC Voltage Input, Open Delta PT Configuration, 1–5 VDC Speed Bias Output, Reduced Upgrade Level Model (excludes power factor control and process control functions)
Product Overview & Introduction
The WOODWARD 9905-709 is a microprocessor-based Digital Synchronizer and Load Control (DSLC) unit designed for three-phase AC generator systems. As a reduced upgrade level model within the DSLC series, it handles paralleling, synchronizing, loading, and unloading functions without incorporating power factor or process control features. It provides precise frequency matching, automated load management, and smooth bumpless transfers during parallel generator operations.
Operational Specifications & Guidelines
Prior to installation or handling, ensure that all electrical power sources are completely de-energized and discharge static electricity from your body by touching a grounded metal object, as the unit is static-sensitive. Mount the 9905-709 module securely inside a protective sheet metal panel control enclosure rated for indoor use, maintaining an operating temperature range between -40^\circC and 70^\circC and storage temperatures from -55^\circC to 105^\circC. Connect the input voltage lines (240 VAC, Open Delta PT configuration), control interfaces, and 1–5 VDC speed bias output wiring strictly in accordance with the manufacturer’s wiring schematics. Verify all terminal connections and ensure system grounding integrity before restoring power.
Startup & Shutdown Sequencing
To prevent breaker tripping, out-of-phase synchronization, or system instability, operators must strictly follow the defined startup and shutdown procedures.
- Startup Sequence:
- Verify all external wiring, potential inputs, control power connections, and safety interlocks are securely fastened.
- Energize the control power supply to the WOODWARD 9905-709 module and wait for the internal diagnostic self-test to complete successfully.
- Start the prime mover and allow it to reach rated nominal speed and thermal stability under governor control.
- Enable the synchronizer module to monitor bus and generator frequency, voltage matching, and phase parameters.
- Engage the automatic synchronizing and load-sharing mode, allowing the unit to execute precise speed bias adjustments via the 1–5 VDC interface and issue the close command to the circuit breaker precisely at the synchronous point.
- Shutdown Sequence:
- Gradually transfer active electrical load away from the generator set back to the main utility grid or companion units until minimum baseline load is achieved.
- Open the main generator circuit breaker manually or via system command to isolate the unit electrically from the busbar.
- Initiate the prime mover cool-down cycle at idle speed for the required duration.
- Issue the stop command to shut down the engine or turbine completely.
- De-energize the auxiliary control power to the module only after the prime mover has come to a complete standstill.
Frequently Asked Questions (Q&A)
- Q1: What specific features or functions are omitted from the WOODWARD 9905-709 model?
- A1: As a reduced upgrade level model, the 9905-709 does not include power factor control or process control functions.
- Q2: What are the input voltage and speed bias specifications for this unit?
- A2: The module operates with a 240 VAC input voltage rating and provides a 1–5 VDC speed bias output.
- Q3: How does the unit handle dead-bus closing?
- A3: It features an automatic dead-bus closure function managed securely through communication network locking techniques so that only one DSLC control is granted permission to close onto a dead bus.
