WOODWARD 9905-373

Overview

WOODWARD 9905-373 is a legacy DSLC Digital Synchronizer and Load Control unit from Woodward, designed for generator paralleling and load management. This specific variant supports 500 Hz PWM speed bias output, 120V voltage sensing input and open-delta PT configuration. WOODWARD 9905-373 is end-of-life hardware, widely supplied as exchange spare for engine generator, CHP and microgrid control cabinet overhaul.

Features

WOODWARD 9905-373 integrates synchronizer and load control functions within a single controller. It enables automatic generator loading and unloading for bumpless transfer during paralleling or island-mode switching. It supports isochronous load sharing among multiple DSLC-equipped generator sets, together with import/export control for tie-line power management. WOODWARD 9905-373 carries built-in VAR and power factor regulation, dead-bus closing capability, and robust sampling performance for distorted non-linear generator waveforms. It uses a dedicated digital network bus for high-speed data exchange between paralleling controllers, and provides programmable load switch and reverse-power trip output logic. WOODWARD 9905-373 works with the Woodward handheld programmer for schedule setup, tuning and fault viewing, and supports serial communication to SCADA for alarm logging and runtime trending. It carries UL and cUL certifications for power generation cabinet installation.

Specs

WOODWARD 9905-373 Platform: DSLC Digital Synchronizer / Load Control. Speed bias: 500 Hz PWM. Voltage input: 120 VAC, open delta PT configuration. Functions: sync check, auto paralleling, load sharing, VAR/PF control, reverse power protection. Communication: DSLC network bus, serial interface. Mounting: panel mount inside genset control cabinet. Accessories: Woodward handheld programmer. WOODWARD 9905-373 is widely supplied as service replacement spare for multi-generator paralleling systems.

Principle

WOODWARD 9905-373 samples generator voltage, bus voltage, CT current and frequency signals continuously. It compares phase angle, frequency and amplitude to issue raise/lower commands to the governor and AVR for synchronization before closing the generator breaker. After closing, the unit regulates real power and reactive power according to load-sharing setpoints. The DSLC network of WOODWARD 9905-373 distributes load demand across all paralleled units to maintain balanced sharing. If reverse power, frequency drift or voltage deviation exceeds limits, the controller triggers alarm and trip logic to protect the generator.

Applications

WOODWARD 9905-373 is deployed for diesel, gas engine and turbine generator paralleling systems in hospitals, data centers, district energy plants and industrial microgrids. It is selected for spare inventory and cabinet retrofit projects for existing DSLC-based genset controls. The successor platform is Woodward easYgen series generator controls.