9905-707

About the 9905-707

This part is in a Woodward series of microprocessor-based Digital Synchronizer and Load Controls. This unit is model number 9905-707, one of the series's reduced upgrade level model numbers. The 9905-707 is designed to be used in the paralleling, synchronizing, loading, and unloading of three-phase AC generator sets, but as a reduced upgrade level model, it does not have power factor control or process control functions.

The 9905-707 DSLC has an input voltage rating of 120 Vac and a speed bias of 1-5 Vdc. This Open Delta PT Configuration control is rated for operating temperatures from –40 to +70 °C (-40 to 158 F) and storage temperatures from –55 to +105 °C (-67 to 221 F).

A few of the 9905-707 functions include:

• Built-in diagnostics
• Setup, metering, and diagnostic capability through a handheld programmer terminal  
• Automatic generator loading and unloading
• Droop, baseload, and isochronous load control capability
•  Reverse power relay.

The 9905-707 offers either phase matching or slip frequency synchronizing. Actual slip frequency and breaker delay values are used to anticipate a minimum phase difference between generator and bus at actual breaker closure for both methods. There is an automatic dead-bus closure function on this unit, where only one DSLC unit is granted dead-bus closing permission through locking techniques over the communications network.

Precautions to protect against static damage should be followed when working with or near the control. Repairs for models 9905-707 are available through AX Control.