How is the ampacity of an underground cable determined, and what factors must be considered beyond the conductor size?

The ampacity of an underground cable is the maximum current it can carry continuously without exceeding its design temperature limit. While conductor size is a primary factor, several other factors significantly influence ampacity. Soil thermal resistivity is a critical consideration, as it affects the cable's ability to dissipate heat. Higher soil thermal resistivity means the cable will run hotter and have a lower ampacity. Burial depth affects the cable's temperature. Shallower burial depths general....