Power Distribution Equipment

A. areas of usage
1. Common reasons for using neutral grounding resistor
a. reducing single phase fault currents which occur in M.V. electrical networks to prevent damages on transformers and generators
b. reducing temporary over voltage occurred by braking instantaneous fault current, providing long-life for switchgear
c. reducing step voltage to a harmless level for staff

Neutral grounding resistors are used for resistance grounding of industrial power system. They are generally connected between ground and neutral of transfomers, generators and grounding transformers. Neutral grounding resistors are used in order to limit maximum fault current to a value which will not damage the equipment in the power system, yet allow sufficient flow of fault current to operate protective relays to clear the fault. Although it is possible to limit fault currents with high resistance neutral grounding resistors, phase to ground short circuit currents can be extremely reduced. As a result of this fact, protection devices may not sense the fault. Therefore, it is the most common application to limit single phase fault currents with low resistance neutral grounding resistors.

B. Features

Stainless-steel resistor elements
Current transformer included (EN60044-1)
Bolted resistor element connections instead of welded connections in order to be able to assemble spare parts on site immediately.