60076-5 — Iec

: The maximum allowable temperature during a fault depends on the insulation class of the materials used (e.g., cellulose paper in oil-immersed units). 3. Dynamic Ability (Mechanical Withstand)

This is a conducted at high-power laboratories like KEMA Labs. iec 60076-5

: Typically, transformers must be designed to withstand these thermal effects for a duration of 2 seconds . : The maximum allowable temperature during a fault