These fuse holders are supporters for fuses with size up to 22 58mm, Then are capable of working under heat caused by lt can also function as a fuse disconnecting switch by multi-phase combination. There are two in/out lines at the RT18N fuse base, providing a power cut function. The RT18L type has a safety lock the fuse carrier when disconnected to avoid wrong operation, it can also be equipped with an indicator, which goes on when the fuse link breaks. Rated insulate voltage up to 690V, Working frequency 50Hz AC,Conventional free air thermal current up to 125A; Compliant with GB13539.1 GB/T13539.2 and IEC60269-1 IEC60269-2.After the plastic-injected case is equipped with contacts and fuse links, the bases are formed by welding or riveting both capable of being multi-phase structured. FB15C, FB16-3J, FB19C-3J, Rt19 are open-structure, and others are semiconcealed structure. There are five fuses sizes available to choose from for the same fuse base of RT18N, RT18B and RT18C, There are two sets of in-out lines for RT18N. One is installed with fuse links fuse links of the according size. The other is a permanent open contacts with double breaking points. The whole base unit can cut the power. Rt18 bases are all DIN rail installed, among which the RT18L is equipped with safety lock against wrong operation in the breaking state.The models, Rated insulate voltage, rated current, and dimensions are shown in figures 9.1~9.14 and Table 9 Width of N-phase combination in Bn=nB .