What happens to voltage and current when a phase-to-phase fault occurs?

When a phase-to-phase fault occurs, the characteristics of voltage and current are significantly affected. In the scenario of a phase-to-phase fault, the fault creates a low-impedance path between two phases of the system. This results in a reduction of voltage across the faulted phases because they are effectively short-circuited, leading to a substantial drop in voltage levels for those phases involved in the fault.

As the voltage drops due to the fault, the current flowing through the faulted path increases dramatically. This can be attributed to Ohm's Law, where a decrease in voltage across a resistor (or in this instance, the resistance created by the fault) results in a proportionate increase in current, assuming the system is still trying to maintain supply levels.

Therefore, the statement that the voltage decreases and current increases effectively describes the behavior of the electrical system during a phase-to-phase fault. Understanding this behavior is crucial for system operators in order to manage the fault conditions properly and take remedial actions quickly.