Earthing Resistor

We offer a wide range of Neutral Grounding / Earthing Resistor panels up to 33 KV.

PURPOSE:

Neutral Grounding / Earthing Resistors are employed in AC Distribution Networks to limit the Restricted Earth Current to a safe value which would flow from the Transformer or Generator star point in the event of an earth fault in the system without exceeding specified temperature limits. In case of short time rating, dissipation is negligible & the temperature rise for the resistor element depends on its capacity to store the energy generated in proportion to the mass & specific heat of the material used. Theses NGR are connected between the neutral point of transformer / generator & the earth.








In no Earth fault condition continious current of 5 % to 10 % of full load current may pass through the resistor due to unbalance in system.
In Earth fault condition the Restricted earth fault current passes through the Metallic Resistor protecting the system till automatic protection takes place by absorbing the earth pressure, protecting the winding etc.

When the current flows continuously for long duration, the temperature of resistor element increases and then stabilizes at a value for which energy supplied is entirely dissipated to the atmosphere. Hence these resistors are designed for allowing maximum heat dissipation