Abstract: The copper shield burst caused by short-circuit breakdown of cable joints is prone to fire hazards in cable tunnels. This paper analyzes a typical 110kV cable joint copper shield burst accident and proposes that the copper shield burst of cable joints is caused by the compound action of two types of states, high temperature and high pressure, and the short-circuit breakdown process is accompanied by the cracking and ionization of insulating materials. The above viewpoint is verfied throgh the short-circuit high-current simulation test of the designed cable joint verifies the above viewpoint, the effectiveness of the current market mainstream use of the cable joint explosion-proof method is analyzed, and the design elements of the cable joint fireproof and explosion-proof are proposed.

Key words: cable joint, short-circuit breakdown, fault analysis, short-circuit simulation experiments, fire and explosion protection