These faults can be caused by natural factors like lightning, tree branches, or animals, as well as technical issues like equipment failure or overload. Single-phasing, drop out. • Protect people (company personnel and the public) and equipment by the proper application of overcurrent protective devices. • Relays operating to trip (open) circuit breakers or circuit switchers, and/or fuses blowing for the occurrence of electrical faults on the distribution system. Principal failure causes are identified through basic statistical and PCA (Principal Component Analysis) is used to find combinations of causes or other factors that describe. Common faults in distribution networks are unexpected problems or failures that interrupt the normal flow of electricity. The most common types of. Sometimes equipment will fail spontaneously for reasons such as chronological age, thermal age, state of chemical decomposition, state of contamination, and state of mechanical wear.