This product is suitable for AC three-phase three-wire, three-phase four-wire, three-phase five-line fire-fighting power distribution system with rated voltage of 1000V and below, rated working current of 100A~5000A and frequency of 50Hz~60Hz. The fire rating is 925 ° C · 45 minutes, which is a must for key fire protection units. It is mainly used in fire protection transmission and distribution systems for high-rise buildings such as chemical, metallurgy, machinery, stadiums, exhibition halls, museums, airports, and stations.