Why is open circuit not allowed on the secondary side of the current transformer during operation?

An open circuit on the secondary side of a current transformer will cause overvoltage (peak of several thousand volts) to be induced on the secondary side, posing a threat to personal safety, the operation of instruments and protective devices, causing secondary insulation breakdown, and causing the magnetic circuit of the current transformer to become supersaturated, the iron core to heat up, and the current transformer to burn out. During processing, the secondary load can be reduced to zero and relevant protection and automatic devices can be disabled. http://www.zbwf.net