Bussmann FWH-400A Semiconductor High Voltage Fuse

The Bussmann FWH-400A semiconductor high‑voltage fuse is a fast‑acting, 400 A protection device intended for 500 V AC/DC circuits and protection of power semiconductors in high‑energy power electronics. It features high‑speed, non‑indicating operation with termination options including blade ends and bolt‑on studs (4-11/32" OAL and 1-1/2" diameter for the bolt‑on variant). The fuse offers an interrupting rating up to 200 kAIC at 1000 VAC and 50 kAIC at 500 VDC, making it suitable for demanding supply rails. Typical applications include DC common bus, DC drives, power converters/rectifiers, and reduced voltage starters. It is listed in catalog and standards references as UL Recognized, CSA, and CE compliant for appropriate configurations.