Dear @Loai

Welcome!

If you have a serious fault that can harm the cables, it will be a short circuit fault at the possible outlets of the grid. Since you already assigned maximum current for each cable then you have to size the circuit breakers or the fuses to interrupt the current path once the current is increases than that specific maximum allowed current. In case of DC sources the and pure resistive load the rate of rise of the current will be determined by the parasitic inductances and capacitances in the system. In case of short-circuit one may have the maximum possible di/dt.

One has to make more investigations to see the variations of di/dt for normal loading and for for case of short-circuit.

Best wishes

Abdelhalim abdelnaby Zekry Thank you so much sir. What I understood from your answer is that a system should be studied on a case by case basis to understand the rate of change of current at either situations, i.e. short circuit, or normal loading, to be able to evaluate both cases at operation. Am I correct?

Yes dear Loai Gomaa this what I said before.

But I would like to expect that the short circuit may have less inductive and capacitive parasitic than the electrical loads. Consequently, if this is the case, the rate of rise of the current at shortcircuit would be larger.

But this still needs verification by more investigations.

Best wishes