Zorc Surge Suppressors

Zorc Surge SuppressorsStrike Logo

Product overview

High Frequency Transient Surge Suppressors
For protection of medium and low voltage motors and transformers


Every year huge losses are incurred by end-users because of insulation failures of medium voltage (3kV – 40kV) motors, and dry-type transformers. This can be caused by:

  • Switching transients associated with vacuum and other switchgear resulting in expensive insulation failures of motors and dry-type transformers.
  • Multiple pre-striking and re-striking (re-ignition) at the motor or transformer terminals.

ZORC Surge Suppressors is a unique high frequency transient over voltage surge suppressor for the protection of motors and transformers from steep wave-front, short rise-time, high magnitude, spikes, surges and other transient voltages, generated by switching, lightning and other sources.



You can view download the PDF by clicking on this icon : pdficon_large


The protective characteristics of ZORC units:

  • Eliminates inter-turn insulation failures
  • Extends the life of machine insulation
  • Provides comprehensive insulation co-ordination at all practical surge magnitudes and rise-times
  • Conforms with both the CIGRë and IEEE motor impulse voltage withstand recommendations
  • Halves the magnitude of steep wave-front surges impinging on the load terminals by providing a matched cable terminating impedance under transient conditions, thereby eliminating refraction of steep wave-front surges (i.e. eliminates voltage doubling effects).
  • Eliminates multiple pre-striking and re-striking transients associated with vacuum and other switchgear, by eliminating reflections of the pre-strike and re-strike current wave-fronts, and thus preventing high frequency current zeros in the contact gap of the switch.


Installed in the following industries:

  • Chemical
  • Petrochemical
  • Underground mining (gold, platinum, coal, other)
  • Surface mining (coal, copper, uranium, iron ore, other)
  • Metal beneficiation (steel, stainless steel, gold, platinum, copper and uranium refineries)
  • Power generation (generators, power station auxiliaries)
  • Pumping (water pumping stations, oil pipelines)


Specific applications on medium voltage motors, generators, and dry-type and oil immersed transformers include:-

  • Fans
  • Pumps
  • Compressors
  • Mills
  • Crushers
  • Refrigeration machines
  • Motor-generator sets
  • Mine winders
  • Conveyors
  • Underground and surface mini-substations and mobile substations
  • Generators
  • Power station auxiliaries
  • Induction & arc furnaces



Benefits provided by ZORC units :

  • Saves money by eliminating production downtime incurred due to insulation failures of motors and dry-type transformers.
  • Protects new motors and dry-type transformers throughout their service life.
  • Extends the life of motor and dry-type transformer insulation if retrofitted to existing motors and dry-type transformers in service.


ZORC Models to suit various voltages : 400V to 40kV.

ZORC units

  • Available in single phase and three phase units. Single-phase versions are suitable for installing in phase segregated terminal enclosures.

Compact and easy to install

  • Special compact versions that can be fitted within most motor/transformer terminal enclosures or switchgear panels.


You can view download the PDF by clicking on this icon : pdficon_large