Low-ohmic resistors RZ for neutral grounding in 6-10 kV networks

Low-ohmic resistors RZ are used for neutral grounding in 20, 35 kV networks that enables relay selectivity, overvoltage limitation at single-phase arcing ground faults and ferroresonance elimination.



Resistor RZ consists of one or two uniform resistive banks.

  • A uniform resistive bank consists of a base placed on four supports.
  • Four insulators OShN-6-80 are fixed on the base.
  • Two vertical posts are fixed on the base insulators.
  • Two insulation plates fixed on the base insulators support protective resistor elements (PRE).
  • Another insulation plate secures the vertical posts fixing PRE on top.
  • An additional insulator (an inlet insulator) using for voltage supply is fixed at the centre of the base.
  • An aluminium bus bar connects (attaches…to) the inlet insulator with a case of the uniform bank placed on the bottom insulation plates.
  • The resistor consists of 6 in-series PRE in 2 parallel circuits.
  • PRE is electrically connected inside the switching box of the uniform bank.
  • Each circuit is grounded from the uniform bank to the base by two grounding bus bars.

Technical specifications

Rated resistance
Operating time under rated currentClimatic conditions according to Russian Standard GOST 15150Life time, not less than (years)
15...250Short-time (not less than 10 seconds)Cold temperatures and Tropical conditions, category 1 (outdoor installation)30


Resistors with required rated voltage, rated resistance, dimensions, for different climatic conditions can be manufactured on request.