Your plant’s 480V load-side distribution system is under a cable testing program for feeders and for branch circuits supplying motors over 30 hp. During each Thanksgiving shutdown, an electrical testing firm conducts cable testing and submits a report identifying suspect cables. During the Christmas shutdown, those cables get replaced.
The plant engineer put six years of results on a spreadsheet and noticed a pattern. About 80% of the “doomed” cables are in the same