Neutral Grounding Resistors limit fault current to ensure safety of workers and equipment in electrical systems.

The purpose of this application;

  • Maximizing operational continuity and safety by limiting the ground short-circuit current to levels that will not damage the transformer and generator.
  • Thanks to the Current Transformer in the Neutral Grounding Resistor, the fault is detected by the relays and the fault duration is defined.
  • Limiting the oscillating and non-oscillating transient voltage fluctuations that will occur with the interruption of the fault current, thus protecting the isolation levels of the equipment in the system.
  • Increasing personnel safety by ensuring that the step voltage in the field is kept at reliable levels
    • Prevention of overheating and mechanical stress of all equipment exposed to fault current

The failure time is usually chosen as 5-10 seconds. This period can be up to 30 seconds in businesses that cannot tolerate sudden power cuts. In fact, in facilities such as hospitals, data centers, textile, cement and injection molding factories, the continuity of the system is very important and the fault time can be selected continuously, provided that the fault current is at a level that will not damage the system in order to detect the fault point without power interruption. For detailed information, you can refer to our product High Resistance Grounding Systems”.


  • Thanks to the resistance blocks mounted on the frame, all modular, rigid cabinet design suitable for lifting from above and below.
  • Thanks to the non-overlapping resistance blocks, each of which is independently mounted to the carcass, it is easy to access and maintain the desired block in the field.
  • High insulation and mechanical resistance against shocks

Application Areas

  • Thermal, Nuclear, Gas Power Generation
  • Hydroelectric, Wind and Solar Power Generation
  • Nominal voltage up to 110/√3 kV
  • Fault current up to 5000 A
  • Fault duration for 5 s, 10 s, continuous or other customer requirements
  • Stainless steel resistance material suitable for extreme ambient conditions, resistant to oxidation and corrosion (AISI304, AISI310, AISI316, AISI430, CrAl, CrNi)
  • Special mechanical and electrical design to withstand high temperature and extreme current values
  • Design and testing in accordance with IEEE C57.32 standard and special specifications
  • Spring-wound, edge-wound or grid resistor elements with a cross-section suitable for the nominal current
  • Fully modular, twisted and stainless bolted structure that can provide uninterrupted electrical continuity at high temperatures.
  • Standard IP23 protection degree of enclosure, available from IP00 to IP55
  • Standard hot dip galvanized steel
  • Lockable door with hinges
  • Special design for ATEX explosive environments

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GR - Neutral Grounding Solutions PDF 1 MB Download