Grounding transformers are typically used to: Provide a relatively low-impedance path to ground, thereby maintaining the system neutral at or near ground potential. Limit the magnitude of transient overvoltages when restriking ground faults occur. Provide a source of ground fault current during line-to-ground faults.

NGR Sensing Resistors are attached in parallel to the Neutral Grounding Resistor. The sensing resistor allows a protective relay which detects resistor failure in a continuous manner. Sensing Resistors are used in combination with neutral grounding resistor monitor relays.