Short Circuit (SC) — an emergency operating mode in an electrical circuit where cable conductors become connected to each other or to ground through extremely low resistance.
Key characteristics:
Sudden resistance drop to near-zero values
Exponential current surge (can exceed rated current by 10-100 times)
Instantaneous heat generation
Common causes in cable lines:
Mechanical insulation damage (during installation or by rodents)
Thermal degradation of insulating materials
Dielectric moisture absorption
Overvoltages (atmospheric or switching)
Hazardous consequences:
Cable ignition and surrounding material fires
Conductor core destruction
Connected equipment damage
Protective device tripping with power outage
Detection methods:
Insulation resistance measurement (megger testing)
Time-domain reflectometry (TDR)
Bridge measurement techniques
Acoustic fault location
Prevention measures:
Regular high-voltage testing
Thermographic inspections
Use of flame-retardant cable insulation
Proper selection and setting of protective devices
