The neutral grounding resistors are designed for neutral grounding of 6-35 kV gridsto limit overvoltage incase ofline-to-ground short circuits (LGSC), to eliminate ferroresonant phenomena and to provide selective operation of relay protection.
The neutral grounding resistor consists of resistive units based on steel grids fastened inside a steel case. The resistor active part is insulated from the case by insulators rated at the preset voltage. There is an option to manufacture cases with protection ratings IP00, IP01, IP20, IP21, IP23, IP54, IP55 and other optional case design styles.
The Penza Plant Telema Gino has developed a separate range of neutral grounding resistors for PJSC "ROSSETI" facilities. These resistors are designed for connecting the 6-20 kV transformer neutral point to the ground,to limit overvoltage in case of line-to-ground short circuits, to provide reliable selective operation of relay protection against short circuits. Lifetime of these resistors is not less than 30 years.