NGR
NGR is basically a Resistance method used in Medium Voltage. Its name elaborate as Neutral Ground Resistor. In most cases it is used as a connection path to the neutral of the transformer. the picture shows inside of a NGR . It grounds the excessive current from the transformer. NGR is protective device for the transformer creating low reisitnce path to send excessive over current to the ground.
NGR earthing value is expected near zero. Separate type 2 by 2 earth pit square type cu plate 3mm thickness drown 8 feet below is industry standard for a earth pit .
