Schneider Electric 9999SX6 Electrical Interlock

9999SX6 is Schneider Electric’s Square D auxiliary contact kit for Type S NEMA motor starters and contactors, designed as an external, field-convertible accessory. It provides a single normally open (NO) auxiliary contact that expands the control circuit without altering the main power path of the starter. As an external auxiliary, the 9999SX6 mounts to the starter and is used to provide signaling and feedback in control logic and sequencing within Square D Type S starter systems. In practical terms, it enables additional control or monitoring contacts—such as feeding a PLC input or indicating circuit status—without modifying the primary switching device, making it a straightforward way to extend the functionality of a Type S assembly.