Table 6 Classification of fault types, causes, and occurrences
From: Transformer faults in tanzanian electrical distribution networks: indicators, types, and causes
Fault type | Fault causes | Fault occurrence | |
|---|---|---|---|
Frequency | Percentage | ||
Discharges of high energy | Significant damage to paper | 78 | 26.2 |
Formation of large quantities of carbon particles in the oil | |||
Metal dissolution and device tripping by gas alarms resulting from perforations due to high energy arcs, flashovers, and short circuits | |||
Cellulose deterioration | Moisture, aging, and overload | 99 | 33.2 |
Partial discharge | Gas bubbles | 72 | 24.2 |
Thermal fault | Overload or oil flow duct blockage | 49 | 16.4 |
Total | 298 | 100 |