Bussmann FWX-400A Semiconductor Fuse

FWX-400A is a high‑speed semiconductor fuse from Bussmann (Eaton), part of the FWX fast‑acting family designed to protect power electronics from overcurrent events. It is rated for 400 A and 250 V, suitable for use in 250 V AC and 250 V DC circuits, delivering rapid interruption when faults occur to shield downstream semiconductors. The FWX-400A carries an I²t pre‑arcing rating of 22,100 A²s and a power loss of 49 W at rated current, reflecting its capability to handle high‑current transients while maintaining thermal performance. This fuse is intended for high‑current semiconductor protection in industrial equipment and power‑electronics applications, helping prevent damage to components by quickly isolating faults. As part of the Bussmann FWX family, the FWX‑400A provides fast‑acting protection in systems that demand reliable, fast clearing of overcurrent events, making it a suitable choice when protecting critical power circuits from damaging surges and short circuits.