Industrial 9998SO1 NSNBC01 Contactor

The Square D 9998SO1 is a dedicated contact kit that provides a single normally closed contact for use with Square D overload relays and retrofit Type S NEMA motor starters. One normally closed contact, Class 9998 Type SO1, is built into the overload-relay block on Type S startersSizes 00–06, making this kit the matching contact component when retrofitting or replacing parts in older installations. Marketed as the Contactor Contact Kit for Overload Relay and Retrofit Starters, 9998SO1 is sold as a repair/replacement part by major distributors and is cataloged under Square D part numbers; it appears in official distributor listings from DigiKey and SupplyHouse, among others. In typical motor-control applications, this contact unit supports signaling or interlock functions within the overload-relay assembly, helping to monitor and control the starter assembly without requiring additional NC contacts or separate assemblies.