Westinghouse FD3100KS30 Molded Case Circuit Breaker

The Westinghouse FD3100KS30 is a 100 A, 3-pole molded case circuit breaker in the FD frame series, delivering thermal-magnetic overcurrent and short-circuit protection for high-amperage branch circuits. It is designed for industrial electrical distribution and is commonly installed in motor control centers, switchboards, and automation panels to protect equipment such as motors and conveyors. This panel- or switchboard-mounted device supports 3‑phase systems at 50/60 Hz and uses KS30 switching configuration for typical MCC and switchgear applications. Common replacements include Eaton FD3100, Siemens HFD3100, and Square D FA34100.