Air Core Neutral Grounding Reactors

Neutral Earthing (Grounding) Reactors are single phase reactors generally connected between ground and neutral of transformers or generators in order to control single line-to-ground faults at a desired level. They achieve this by resisting current flow through inductive elements.

Neutral Grounding Reactors are used in order to limit line-to-ground 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. If the circuit is balanced, current flow through the reactor will be zero, thus, there will be no losses.

Neutral Grounding Reactors reduce short circuit stresses on substation transformers which is one of the most widespread type of fault in an electrical system.

A loaded generator can develop a third-harmonic voltage. Providing impedance in the grounding path with a Neutral Earthing Reactor, can limit the third-harmonic current component.


Area of Usage


  • Reducing single phase to earth fault currents which occur in electrical networks to prevent damages on transformers and generators
  • Reducing temporary over voltages formed by braking instantaneous fault currents
  • Providing long-life for switchgears
  • Reducing step voltages to a harmless level for personel




  • Perfect mechanical strength to withstand high short-circuit forces
  • Limited temperature rise enables longer lifetime
  • Special surface protection against UV and pollution Class IV areas
  • Maintenance-free design
  • Low noise levels


Technical Specifications
Voltage Up to 170 kV
Current Up to 20 kA*
Type Air core, dry type
Frequency 50 Hz / 60 Hz
Installation Indoor / Outdoor
Winding Aluminium or copper winding
Painting RAL 7035 or other colors on demand
Construction Epoxy impregnated, fiberglass encapsulated construction
Temperature -40°C to 55°C
Insulation Class F class or custom
Cooling AN (air-natural) cooling method

- Taps

- Enclosure available on demand

- Available desings as per IEEE, IEC and others

- DIN or NEMA terminal configuration

*Consult factory for higher values.