Grounding the Neutral of Electrical Systems Through Low-Resistance Grounding Resistors: An Application Case

It seems common knowledge that three-phase short-circuit currents are the worst possible scenario for electrical systems. In reality, single-phase ground-fault currents may be significantly more intense than three-phase fault currents. With the occurrence of high single-phase fault currents, severe damage could be caused to the iron cores of electric machines included in the zero-sequence fault loop. The method of neutral low-resistance grounding will be discussed by applying a step-by-step calculation procedure to an actual case, in order to properly size the grounding resistor, thereby limiting the fault current.