In most short-circuit scenarios (typically under 1 or 2 seconds), it is assumed no heat escapes the conductor. The permissible current ( IADcap I sub cap A cap D end-sub ) is calculated as:
cap I sub cap A cap D end-sub equals the fraction with numerator cap K cross cap S and denominator the square root of t end-root end-fraction cross the square root of l n open paren the fraction with numerator theta sub f plus beta and denominator theta sub i plus beta end-fraction close paren end-root : Cross-sectional area of the conductor ( m m squared : Duration of the short circuit (maximum 5 seconds). : Initial and final temperatures ( raised to the composed with power cap C : Material-dependent constants for copper or aluminum. Non-Adiabatic Effects iec 60949 pdf free download exclusive
= The non-adiabatic factor. This factor accounts for the heat absorbed by the surrounding media. Critical Factors to Consider In most short-circuit scenarios (typically under 1 or