Time: 20:00
Important one liner (Types of Fault in Underground Cable)
- Phase-to-earth fault occurs when one conductor touches the ground conductor.
- Phase-to-phase fault happens when two conductors short circuit together.
- Double phase-to-earth involves two phases both contacting earth.
- Three-phase fault is a balanced short involving all three conductors.
- Conductor break fault is an open circuit due to line interruption.
- Sheath fault arises from damage to the cable’s metallic sheath.
- Inter-turn fault happens in cable winding turns internally.
- Metallic return fault uses the cable’s sheath as return path.
- Capacitive unbalance arises from uneven insulation capacitance.
- High resistance earth fault limits ground current through resistance.
- Low resistance earth fault results in high ground fault currents.
- Transient fault is temporary and clears when arcs extinguish.
- Permanent fault requires cable repair or replacement for restoration.
- Mixed fault combines phase-to-earth and phase-to-phase elements.
- Symmetrical faults are balanced short circuits across all phases.
- Asymmetrical faults involve unbalanced phase conditions.
- Line-to-line-to-earth fault includes two phases shorting to earth.
- Single line-to-earth fault assumes a low impedance ground path.
- Sheath insulation breakdown is detected via sheath voltage monitoring.
- Open conductor fault shows loss of continuity in the circuit.
- Three-phase-to-earth fault involves all three touching ground suddenly.
- Permanent sheath fault often means metallic sheath joint failure.
- Mixed earth-phase fault is both phase-to-phase and earth combined.
- Diagnosis uses VLF, HVDC, or time domain reflectometry methods.
- Preventive maintenance reduces likelihood of underground cable faults.
Keywords: types of fault in underground cable, cable fault diagnosis, short circuit underground cable, earth fault cable, cable insulation failure, armoured cable fault, cable fault quiz, cable fault analysis, underground cable fault prevention, cable fault detection