submersible pump cable mining

A stacker-reclaimer at a Newcastle coal export facility began experiencing intermittent loss of load cell signals, causing the control system to alarm and sometimes force the equipment into manual operation. Initial inspection found no obvious cable damage, and preliminary multimeter continuity tests showed the pilot conductors intact. However, when the equipment was operated at full speed during testing, the pilot conductor resistance measurement jumped from approximately 8 ohms to 45 ohms, demonstrating clear intermittency. A TDR test located the fault at approximately 450 meters along a 600-meter cable run. Detailed microscopic analysis of a cable section removed from the fault location revealed fatigue-induced microfractures in multiple copper strands within the pilot core. The root cause was identified as excessive vibration from poorly lubricated reeling drum bearings. The cable was successfully spliced at the fault location using a mid-cable connector kit, and bearing maintenance was performed to address the underlying vibration problem. The repaired cable has since operated successfully for over three years without additional pilot core failures.