I_sc adiabatic calculation

The formula of adiabatic heating, is presented in the following general form:

where:

I_AD: is the short circuit current (rms value during the short-circuit) calculated in adiabatic hypothesis (A);

t: is the short-circuit duration (in seconds);

K: is the constant that depends on the material of the component current conductor;

• For aluminum conductors we can use the value of 148 A.s^1/2/mm²
• For copper conductors we can use the value of 226 A.s^1/2/mm²

S: is the section of the component geometry current conductor, the conductors will be taken to the nominal section, and displays a section of wire (see section screen calculation);

: is the final temperature of the circuit (°C). Typically 250 °C for the conductor and 210 °C for the screen;

:is the initial temperature of the circuit (°C). Steady at maximum load, we can assume 90 ºC conductor (XLPE cables) and 80 °C on the screen;

: is the inverse of the coefficient of variation of resistance with temperature component of current conductor ºC (K);

 

• For aluminum conductors we can use the value of 228 K
• For copper conductors we can use the value of 234,5 K