Description
Product Datasheet & Technical Parameters
- Brand: WOODWARD
- Model: 9905-893 (DSLC)
- Series: DSLC Digital Synchronizer and Load Control Series
- Product Name: Digital Synchronizer and Load Control Unit
- Place of Origin: United States
- Condition Status: Brand New / Factory Original Surplus (Obsolete Model Support)
- Dimensions: Approx. 460.65 mm x 264.16 mm x 58.42 mm (Sheet Metal Back Plate Enclosure)
- Weight: Approx. 6 lbs 14 oz (3.1 kg)
- Original Region: USA Manufacturing Plant
- Input Voltage & PT Config: 120/240 VAC input voltage, WYE PT Configuration
- Speed Bias Output: 500 Hz PWM Speed Bias output
📖 Product Overview & Description
The Woodward 9905-893 is a microprocessor-based Digital Synchronizer and Load Control (DSLC) module designed for three-phase alternating current industrial generators. It combines multiple power management functions into a single package, including true RMS power sensing, automatic generator loading and unloading, isochronous/droop load control, and dead-bus closing functionality.
Equipped with a WYE potential transformer (PT) configuration and a 500 Hz PWM speed bias output, this unit interfaces directly with prime mover electronic speed controls and automatic voltage regulators (AVRs). It supports both phase matching and slip frequency synchronizing methods to deliver smooth parallel operations and bumpless load transfers.
🛠️ Operating Specifications & Usage Methods
Proper installation and correct wiring practices are essential for optimal system performance. All PT sensing lines (120/240 VAC), digital communication lines over the Local Operating Network (LON), and control inputs must use shielded twisted-pair cables routed away from high-voltage distribution lines and variable frequency drives to prevent electromagnetic interference. The module must be securely housed inside a protective industrial enclosure.
During system commissioning, configure all operational parameters—including loading rates, dead-bus parameters, synchronization thresholds, and power control modes—using an authorized handheld programmer terminal. Verify signal integrity across all input channels before conducting live system start-ups or synchronizing sequences.
⚡ Startup & Shutdown Sequence
Following a structured startup and shutdown sequence protects the prime mover, generator windings, and electrical switchgear from mechanical shock and electrical transients.
- Startup Sequence: First, inspect all mechanical linkages, fuel valves, and safety interlocks. Energize the DC control power supply to the 9905-893 unit and verify that all status diagnostics indicate normal operation via the handheld programming terminal. Crank and start the prime mover, bringing it up to its rated operational speed and nominal voltage. Engage the synchronization mode (utilizing slip frequency or phase matching) to allow the unit to monitor bus and generator parameters, automatically issuing breaker close commands once conditions safely align.
- Shutdown Sequence: Begin by ramping down active power generation through controlled unloading commands until minimum load is achieved. Open the main generator circuit breaker to decouple the unit from the shared electrical busbar. Allow the prime mover to run at a no-load idle state for thermal stabilization cool-down. Issue the stop command to shut down the engine, and finally de-energize the control power supply once all equipment has come to a complete standstill.
❓ Frequently Asked Questions (Q&A)
- Q1: What PT configuration and voltage input does the Woodward 9905-893 use?
- A1: It utilizes a WYE PT configuration and supports a 120/240 VAC input voltage rating.
- Q2: What type of speed bias output does this specific model feature?
- A2: The unit features a 500 Hz PWM speed bias output for precise governor communication.
- Q3: How does the unit handle dead-bus closing?
- A3: It includes an automatic dead-bus closure function where a designated DSLC control is granted closing permission through exclusive locking techniques across the digital communication network.
