High Resistance Grounding... Is It More Than Just a Big Heater?

09/01/2008
As part of our standard testing and inspection routine during maintenance outages and commissioning, we inspect and test the neutral grounding resistor, commonly referred to as a NGR. A NGR is connected to the X0 point or star connection point of a wye-connected transformer. The purpose of the NGR is to control the amount of current flow into a ground fault in the event of insulation failure of one of the normally energized conductors to ground.