What factor does not affect the available fault current at the end of a circuit conductor run?

The available fault current at the end of a circuit conductor run is primarily influenced by several physical characteristics of the conductor and the circuit. Factors such as the resistance of the conductor, its length, and its size directly impact the amount of current that can flow during a fault condition.

The resistance of the conductor affects the amount of current that can pass through it; higher resistance results in lower fault currents. Similarly, the length of the conductor run impacts the total resistance—longer runs have more resistance, which can reduce fault current. The size of the conductor matters as well—larger conductors have lower resistance, allowing more current to flow during a fault.

On the other hand, the color of the conductor insulation does not influence the conductor's electrical characteristics or the available fault current. Insulation color serves mainly for identification and safety purposes, rather than affecting the physics of electrical current flow. Therefore, it is the one factor that does not have a bearing on the available fault current at the end of a circuit conductor run.