Bob
13.8 & 4160 serve switchgear in other buildings from the power plant. I feel since they are feeders high voltage or not they require equipment grounding .The 600 volt no question EGC per 122 .As far as terms on HV the cable is rated at 90% 105% but most if not all terms are rated at 90% the 105 can be used for derating. I have brought several of theses questions up to the code panels but found out theres not a great deal of good info out there on H.V. questions. I am aware of the 60% on terms on older panels . Thanks for the interchange of ideas. The wires by the way each in there own 4 inch.
