Bussmann FWH-125B Fast Blow Cartridge Blade Fuse

The Bussmann FWH-125B is a fast-acting, blade-end cartridge fuse from the Eaton Bussmann FWH high‑speed family, rated for 125 A and 500 V. Its blade-end X blade-end configuration is designed for compatibility with common blade fuse blocks. The device carries an I²t rating of 800 A²s and, at rated current, dissipates about 25 W of power. It supports high fault currents with a maximum interrupting rating of 200 kAIC at 1000 VAC and 50 kAIC at 500 VDC. The FWH-125B is rated for 500 VAC/dc (UL), aligning with common industrial and commercial power-electronics protection requirements. Distributors such as DigiKey and Mouser list the FWH-125B, confirming its availability in the market. In practice, this model is used to protect current‑sensitive semiconductor devices and power‑electronics circuits in high‑current applications, consistent with the FWH series’ semiconductor fuse designation.