Sub-cycle detection of incipient cable splice faults to prevent cable damage

This paper presents an innovative method for subcycle detection of incipient cable failures caused by self-clearing faults occurring in cable splices due to insulation breakdown. Because of their short duration, conventional overcurrent protection will not detect these types of faults. The protection scheme described in this paper has been integrated into a universal relay platform. It is fast enough to operate for sub-cycle faults and has the logic to differentiate them from other types of faults. Imminent cable failure can be detected.