Comparison of Surge Arrester Technologies

Surge arrester (internal lightning protection) systems are one of the most important building blocks of protection against lightning and overvoltage. With developing technology, surge arrester technologies have also developed and started to become smarter. Now let’s examine these technologies.

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1-Varistor Technology

Varistor is one of the oldest and most frequently used surge arrester technologies. A varistor is actually a non-linear resistor. Resistance values change with heat. It is an insulator in normal conditions. When the voltage coming to the varistor passes the threshold value, the resistance value of the varistor drops rapidly. The fastest feature of varistors is that they react within nanoseconds, meaning they are very fast.

Advantages

They give a fast response to overvoltage.

Disadvantages

Their current carrying capacities are limited. They generally become disabled as a result of the impulse they receive. Generally, the cartridges of surge arresters with this technology are changed frequently. This leads to additional cost and loss of time.

Metal oxide varistors formed the basis of the first surge arresters.

2-Spark Gap Technology

Spark gap technology is a chemical technology. They dampen the incoming impulse currents thanks to carbon rings. Products with spark gap technology do not become disabled. It has unlimited life technology.

Advantages

Discharge capacities are high. Performance is high. It does not become disabled as a result of an impulse.

Disadvantages

Response time is slower compared to varistors. It may miss incoming impulses.

3-SafeTec Technology

In LV Surge Arrester systems, gas discharge tube (GDT) technology is of great importance parallel to semiconductor technology. The most correct systems are the joint operation of these 2 systems and the circuit elements not burning due to the heat effect of the lightning impulse. The giant company of the Raycap group brought a new breath to surge arrester technology with ISKRA Safetec products. After eliminating the temperature effect of the lightning impulse reaching 28,000 Celsius with the TC circuit, it placed the GDT technology, which protects the varistors and offers an Airbag effect, as the first element to meet the system and took the varistors that react in less than 25ns under protection. In the 2nd line after this protection, a circuit structure forming the basis of Safetec technology emerged, where GDT and Varistor work like 2 different circuits and detect lightning and grid impulse characteristics separately.

You can get information about Safetec technology from our video below.

https://www.youtube.com/watch?v=DEcxpTyU62g&t=2s