Schneider Electric 9999 SX-8 Electrical Interlock

Schneider Electric's Square D 9999 SX-8 electrical interlock is a Type S NEMA motor starter/contactor featuring an isolated 1 NO/1 NC auxiliary contact that can be wired for external operation and field-converted. Designed for Type S installations, this interlock version supports Size 00–7 configurations, enabling integration with standard Square D 9999 starters. It provides a signaling path via its 1 NO/1 NC contact to coordinate operation between a main disconnect and control circuit in motor control circuits. The 9999 SX8 designation identifies the interlock variant with a field-convertible external contact arrangement, suitable for use in industrial control panels relying on Square D equipment.