Surge Arresters

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Our range of Accessories:

  • Insulating Base
  • Surge Monitor
  • Clamps for all cable sizes
  • Disconnector
  • Insulating mounting clamp
  • Steel mounting clamp
  • Galvanized support structures (Pipe type and Angle type)

 

Application

Over-voltage protection is of key importance to Utilities to improve their network quality and reliability. Surge Arrester, being a protective device to limit surge voltages on equipments by discharging or bypassing surge currents, plays an important role as an industrial product. Surge arrester, like a fuse in a house hold, is installed to protect the connected equipment by even burning out itself occasionally—often misunderstood for this reason—during the process. A very basic depiction of the application is shown in the image below:

Zinc Oxide Varistor

The heart of the surge arrester are the highly non-linear Metal Oxide (MOV) blocks designed to withstand the electric surges, housed in a non-porous electrical porcelain / polymer insulator along with proper anchoring parts and an effective sealing system. The principal chemical formulation of the Zinc Oxide varistor is made of approximately 95% ZnO, plus Bi2O3, Sb2O3, Co2O3, MnO2, Cr2O3, and NiO as additives. All these oxides are mixed in a plastic earthenware jar with zirconium and pure ion-free water distilled for 24 hours. Rare earth oxide (Pr6O11 or Nd2O3) too can be added to the principal composition.

 

 

 

 

 

 

 

Our test lab is capable of conducting all routine and few type tests for the arresters. Our customers are given a free hand to choose any sample out of the production area and we can even conduct a few type tests in front of them. Below is the list of the equipments present in our lab along with their pictures: 

1. 1200kV Impulse Voltage and Current Generator: This machine is one of its kind worth $500,000 that can generate any waveform of upto 1200kV to simulate an impulse voltage. What makes it so special is that with a few changes in the circuitry, it can also produce both, voltage & current impulse, upto 600kV x 10kA; and hence we can simulate a live working condition that the arrester faces when it is in the field.

 2. 150kA Impulse Current Generator: This machine is used to generate impulse currents. We study the response of ZnO blocks to the various waveforms of impulse passed through them. 

3. 300kV Power Frequency: Power frequency voltages of upto 300kV can be generated and the equipment can be tested for its insulation levels. Our all-enclosed setup is capable of detecting any partial discharge up to the level of micro amps. The same setup is used to detect leakage current in an arrester. 

4. Accelerated Ageing Setup: We can simulate the environment that a Zinc Oxide block will face by simulating the temperature and moisture in this controlled test setup.