Square D 9999SX6 Electrical Interlock Type S NO

Square D's 9999SX6 is an external auxiliary contact kit for Type S NEMA motor starters/contactors, delivering a single normally open (NO) contact that is field-convertible to fit control-circuit needs. Designed to accompany the Square D Type S family, this accessory is used to provide auxiliary signaling and control-circuit feedback in industrial panels, and for Type S sizes 3–7 it serves as the holding circuit contact. The 9999SX6 is marketed as an auxiliary contact for external, field-convertible use with Type S devices, enabling integration of additional control logic without replacing the main contactor. As part of the Type S accessory lineup, it helps extend the functionality of motor-control assemblies by adding a dedicated NO contact to monitor coil status and drive related control circuits within electrical control systems.