Healthy insulation within the instrumentation exposed to any transient over voltages of little time length because of switching and lightning strokes, direct or indirect. Insulation failure is also happened, resulting in terribly large fault current. This current is also quite ten times the nominal current of the instrumentation.
Ageing of power equipment's could reason breakdown of it uniform at usual power frequency voltage.
The fault should be cleared as quickly as potential. Several equipments might be wrecked if the fault isn't cleared speedily. The damaging of the faults depends on the sort of the fault, as example the 3 part short circuit is that the most dangerous fault as a result of the short current is maximum. a number of the results of short current area unit listed here under.
- Due to heating and therefore the mechanical forces established by faults, electrical equipment's like bus bars, generators, transformers are going to be broken.
- Negative sequence current rises from unsymmetrical faults will result in heating.
- Voltage profiles are also condensed to undesirable limits as a outcome of faults. A frequency drop could result in instability.