Design and use of MV current-limiting fuses

MV current-limiting fuses are primarily used to protect transformers, motors and other loads. There is no need to list all the advantages which make this device so successful. Its low cost and its limiting characteristics, which significantly reduce current amplitude and the energy released in the event of a short-circuit, are among its most lauded features. There is currently no other device on the market to rival or even come close to the performance of the fuse in medium voltage (3.6 to 36 kV) applications. However, this device does have limits which should not be exceeded. The reluctance of some users to use fuses is often due to previous bad experiences caused by a failure to follow certain basic rules of construction or use resulting in faults during operation. It is then only after carefully considering the design requirements of a fuse link that users become aware of any rules of use, which, if observed, will ensure the fuse’s optimum faultless operation.