Electrical Engineers need to know the importance of X/R ratio in doing fault calculations. This ratio can actually determine the peak asymmetrical fault current. Accordingly, the asymmetrical fault current can be way higher than the symmetrical fault current.
The Importance of X/R Ratio
It is important to note that the dc component of the fault current decays rather rapidly, reaching an insignificant value in a matter of 3 to 5 cycles of the power frequency. In this process, the rate of decay is determined by the X/R ratio of the circuit at the point of fault. That means, if the value of the ratio is higher then the DC component decay is slower which prolongs the danger as a result of the fault.