Mersen Announces Expanded Ratings in Class RK1 Reducer Fuse Series

June 24, 2025

Global Electrical Power and Advanced Materials leader Mersen is pleased to announce the expansion of the 600V ratings to its first-to-market Class RK1 Reducer Fuse product series. The newly released 600V ratings provide a permanent and reliable solution and are designed to be used in all applications where standard UL Class RK-1, RK-5, K-5, and H fuses are typically employed.

Certified as Special Purpose UL/CSA Listed Class RK1 fuses, these reduced current rating fuses are designed to fit into the next larger size fuse holders, providing the same high reliability performance, durability, and arc flash mitigation as standard Class RK1 fuses.

Reducer Fuses can help achieve greater efficiency within a facility and are ideally suited for start-up or newly expanded manufacturing facilities that are ramping up production and electrical power demand. Upon approaching full capacity, the reduced rating Reducer Fuses can be readily replaced by higher standard rating fuses of the same body size, thus eliminating the need to replace the fuse panel.

Another key benefit of RK1 Reducer Fuses is that they are ready to install and replace directly out of the box, minimizing production downtime.

Mersen is the only fuse manufacturer to offer Reducer Fuses. You can order Class RK1 Reducer Fuses from your local Mersen supplier, along with the Class J Reducer Fuse and Class RK1 and Class J Fuse Reducer accessories.

For more information about Mersen Reducer Fuses, please visit the Class RK1 and Class J Reducer Fuse web pages.