Failures And Causes Of High Voltage Switchgear

Opening and closing faults: This type of fault is caused by the circuit breaker body. For low-oil circuit breakers, it mainly manifests as oil injection short circuit, arc extinguishing chamber burning, insufficient breaking capacity, explosion during closing, etc. For vacuum circuit breakers, it manifests as leakage of arc extinguishing chamber and bellows, reduced vacuum, restrike of cut-off capacitor bank, and rupture of ceramic tube.

Insulation fault: It manifests as external insulation to ground flashover breakdown, internal insulation to ground flashover breakdown, phase-to-phase insulation flashover breakdown, lightning overvoltage flashover breakdown, porcelain bottle casing, capacitor casing flashover, pollution flashover, breakdown, explosion, lifting rod flashover, CT flashover, breakdown, explosion, porcelain bottle breakage, etc.

Current-carrying fault: The main reason for current-carrying fault at 7.2~12 kV voltage level is poor contact of Power distribution cabinet isolation plug, resulting in contact melting.

External force and other faults: including foreign body impact, natural disasters, small animal short circuit, etc.