MS 375 application field and working principle

MS 375 type fuses are advanced type high breaking capacity (HBC) fuses that are designed for high fault level applications. MS 375 fuses are class up to 40E rating and are suitable for industrial and public electricity distribution networks up to a fault level of 50kA. MS 375 type HBC fuse application fields include, but not limited to, stator motor starting, capacitor switching, ring main unit switching, short-circuit current limiting device protection, and earth fault loop impedance monitoring.

The MS 375 type HBC fuse is an all-in-one fuse-link. It is designed for ease of installation in distribution boards or enclosed panel systems that have a built-in fusing system. The fuse body is made of polycarbonate material and has two consecutive linking bands of tin-plated copper which provides a reliable interruption of the current under abnormal conditions. The fuse operates on the principle of current-limitation. When the current reaches a value higher than the pre-set rating of the fuse, the fuse element melts and closes the circuit. This prevents total overloading and reduces fault level currents beyond a certain level.