WOODWARD 9905-028 Retrofit-Ready Load Sharing Module

WOODWARD 9905-028 Retrofit-Ready Load Sharing & Speed Control Module for EasyGen Series Control Systems

The WOODWARD 9905-028 is a precision-engineered Load Sharing and Speed Control Module designed for seamless integration into EasyGen-series generator control systems. As legacy generator management platforms approach end-of-life or face discontinued spare parts availability, the 9905-028 serves as a proven retrofit solution for facilities seeking to modernize their power generation control infrastructure without a full system overhaul. Whether you are replacing a failed unit, upgrading an aging control cabinet, or migrating from an obsolete parallel generation architecture, the 9905-028 delivers the compatibility, reliability, and field-proven performance that industrial operators demand.

Engineered to WOODWARD’s exacting standards, this module supports isochronous load sharing across multiple generator sets, enabling precise real and reactive power distribution in both island and grid-parallel modes. Its compatibility with the broader EasyGen controller family — including the EasyGen-1000, EasyGen-2000, and EasyGen-3000 series — makes it a versatile drop-in candidate for a wide range of genset control panel configurations. Engineers planning a retrofit must verify terminal wiring assignments against the existing panel drawings, confirm the module address settings on the backplane, and validate communication link integrity with the site SCADA or HMI system before commissioning.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

A successful retrofit of the WOODWARD 9905-028 into an existing generator control panel requires systematic pre-installation planning. Begin by auditing the existing control cabinet layout: identify the current backplane or DIN rail configuration, document all terminal connections on the outgoing module, and photograph the wiring harness before disconnection. In many legacy installations, the 9905-028 operates alongside a WOODWARD EasyGen-2000 or EasyGen-3000 master controller, which manages the overall genset sequencing and protection logic. Confirm that the replacement module’s firmware version is compatible with the installed EasyGen controller revision to avoid communication handshake failures on the CAN bus link.

Power supply integrity is a critical pre-check. The 9905-028 requires a stable 24 VDC auxiliary power supply; verify that the existing panel power supply module — often a WOODWARD or third-party 24 VDC rail-mount PSU — can sustain the additional load without voltage droop under peak demand. If the panel also houses a WOODWARD 2301D Load Sharing and Speed Control unit or a GAC ESD5500E speed controller as part of a hybrid architecture, ensure that the load sharing reference signals are correctly isolated to prevent cross-interference during the transition period.

For sites running Modbus RTU communications over RS-485, verify that the 9905-028’s node address does not conflict with other devices on the bus, including remote I/O modules, power meters, or the site SCADA gateway. If the existing HMI — whether a WOODWARD InPower service tool interface or a third-party panel HMI — has hardcoded register maps for the outgoing module, update the HMI configuration screens to reflect the new module’s register layout before going live. Failure to update HMI data mappings is one of the most common causes of post-retrofit alarm floods and false trips.

Where the retrofit involves expanding I/O capacity — for example, adding discrete inputs for new protection relays or analog outputs for AVR trim signals — consider whether the existing backplane or terminal block arrangement can accommodate additional wiring without exceeding the panel’s IP rating or cable management capacity. In some EasyGen-based architectures, a WOODWARD 9905-032 or similar expansion accessory may be required to support additional analog I/O channels. Ensure all field wiring is re-terminated with appropriate ferrules and labeled per IEC 60445 conventions to facilitate future maintenance.

Downtime Control During System Migration

Minimizing unplanned downtime during a 9905-028 module swap is achievable with disciplined pre-staging and a structured cutover procedure. Before the maintenance window opens, pre-configure the replacement module offline using WOODWARD’s InPower software: load the saved parameter file from the outgoing unit, adjust any site-specific droop, gain, and deadband settings, and verify the configuration against the original commissioning record. This offline pre-staging step alone can reduce on-site commissioning time by 60–80% compared to a cold-start configuration approach.

During the cutover, transfer generator load to an alternate source or reduce to minimum load before isolating the control module. Preserve the original PLC or EasyGen controller program by exporting a backup to a USB drive or engineering laptop before any hardware changes are made — this protects the site’s control logic in the event that the new module requires a firmware update that resets default parameters. After physical installation, perform a staged power-up: energize the 24 VDC auxiliary supply first, confirm module self-diagnostics pass, then re-establish the CAN bus and Modbus communication links before reconnecting the speed reference and load sharing signal wiring.

Field verification should include a no-load speed stability test, a load acceptance test at 25%, 50%, and 100% rated load, and a parallel synchronization check if the site operates in grid-parallel mode. Document all as-found and as-left parameter values in the site maintenance log. With proper pre-staging, a 9905-028 retrofit can typically be completed within a 4–6 hour planned maintenance window, keeping production impact to a minimum.

Retrofit Support FAQ

Q1: Is the WOODWARD 9905-028 a direct drop-in replacement for the original unit?
In most EasyGen-series installations, yes — the 9905-028 is dimensionally and electrically compatible with the original module footprint. However, you should verify the firmware revision of your EasyGen controller and confirm that the terminal wiring assignments match your panel’s as-built drawings. Minor wiring adaptation may be required if the panel was modified after original commissioning.

Q2: What commissioning steps are required after installation?
After physical installation, restore the saved parameter file using InPower, verify the module address and communication node ID, calibrate the speed reference input, and confirm load sharing gain settings match the site’s generator set rating. Perform a staged load test before returning the unit to full automatic operation. All commissioning results should be recorded and filed with the site maintenance documentation.

Q3: Can the 9905-028 be used with third-party AVRs and governor actuators?
Yes, the 9905-028 is compatible with a range of third-party automatic voltage regulators (AVRs) and electronic governor actuators, provided the analog signal levels (typically 0–5 VDC or 4–20 mA) are correctly matched. Consult the WOODWARD 9905-028 product specification sheet and your AVR manufacturer’s interface guide to confirm signal compatibility before wiring.

Q4: What does the 12-month warranty cover?
The 12-month warranty covers manufacturing defects and functional failures under normal operating conditions from the date of shipment. It does not cover damage resulting from incorrect installation, overvoltage events, or unauthorized modification. All units are functionally tested prior to shipment. For warranty claims or technical support, contact SMARTNEXMSK at sales@smartnexmsk.com or +86 18259474341.

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Contact: sales@smartnexmsk.com | +86 18259474341