Is the available fault current at the end of a circuit conductor run affected by the size or length of the conductor?

The assertion that the available fault current at the end of a circuit conductor run is not affected by the size or length of the conductor is fundamentally based on the principle that fault current is determined primarily by the source's capabilities rather than the specific characteristics of the conductor, such as its size or length.

In electrical systems, when a fault occurs, the fault current is predominantly influenced by the characteristics of the power source and the impedance in the circuit leading up to the fault point. While the conductor's size and length can impact factors such as voltage drop and resistance, the available fault current remains tied to the voltage level and the short-circuit impedance of the overall circuit.

In practical terms, when determining the available fault current, it is more about the system's configuration, including transformers, generators, and the total resistance and reactance of the circuit elements up to the fault location. Thus, changes in conductor size or length, while they can affect other parameters in the system, do not significantly alter the fault current available at the end of the conductor run.