Common Faults Of Cable

Common faults of cable line there is mechanicaldamage to insulation, insulation damage, damp,decay, voltage, cable insulation overheatingfault. When the failure occurs when the line,cut off the power cable fault, look for troublespots, checking and analysis of the fault andrepair and test, which cuts out until the faultis eliminated in order to restore power.
Cable fault the most direct reason is insulatedto reduce breakdown.
Are:
A, operating over-load. overload for a long time, will make the cable temperatures, aging,resulting in breakdown of insulation, reduceconstruction quality.
B, electrical connection: cable does not meetrequirements of construction technology, cablehead poorly sealed, moisture intrusion cableinside the cable insulation performance; failed to take protective measures when laying cables,protective layer is damaged, insulation reduces.
C, construction: ditch poor drainage, cableprolonged water immersion damage insulationstrength; too little, bending radius of thecable is not enough, long-term compressionbreakage. mainly municipal constructionmachinery in rough construction, dig injurybroken cables.
D corrosion. protective layer subjected tochemical corrosion or corrosion of the cable for a long time, resulting in failure of protective,insulated down.
Annex e, the cable itself or the cable head poorquality, poor cable end seal and insulationadhesive dissolves, crack, cause resonance at the station for line break fault linecapacitance and transformer magnetizinginductance and Capacitance to ground constitutesa resonant circuit, so as to stimulateferroresonance.
Break fault caused by hazards
Break resonance in serious situation Xia, high frequency and base frequency resonance overlay, can makes had pressure site value reached phase voltage [p] of 2.5 times times, may led to system neutral points displacement, winding and the wire appeared had pressure, serious Shi can makes insulation Flash complex, arrester explosion, electrical equipment damaged. in some situation Xia, load transformer phase sequence may reverse, also may will had voltage passed to transformer of low voltage side, caused against.
pressionbreakage. mainly municipal constructionmachinery in rough construction, dig injurybroken cables.
D corrosion. protective layer subjected tochemical corrosion or corrosion of the cable for a long time, resulting in failure of protective,insulated down.
Annex e, the cable itself or the cable head poorquality, poor cable end seal and insulationadhesive dissolves, crack, cause resonance at the station for line break fault linecapacitance and transformer magnetizinginductance and Capacitance to ground constitutesa resonant circuit, so as to stimulateferroresonance.
Break fault caused by hazards
Break resonance in serious situation Xia, high frequency and base frequency resonance overlay, can makes had pressure site value reached phase voltage [p] of 2.5 times times, may led to system neutral points displacement, winding and the wire appeared had pressure, serious Shi can makes insulation Flash complex, arrester explosion, electrical equipment damaged. in some situation Xia, load transformer phase sequence may reverse, also may will had voltage passed to transformer of low voltage side, caused against.