Operating Principle of Surge Arresters

LV Surge Arresters , i.e., internal lightning protection systems, are passive elements that provide protection against lightning and sudden overvoltage impulses. Surge arresters cannot be thought of as a disconnector, fuse, or breaker. When the surge arrester performs its duty, it does not cut the circuit; it takes the impulse upon itself, dampens it, and transmits it to the ground. So how does the surge arrester perform its duty?

The first emergence of surge arresters was made possible by varistor technology. Varistor technology, which is still used today, is important for its fast response to impulses. A varistor, which normally has high resistance, drops in resistance when it receives an impulse and takes the impulse upon itself. If varistors receive impulses beyond their capacity, they can easily burn out and become unable to perform their surge arrester duty.

A Different Surge Arrester Technology: SafeTec

The most frequent problems experienced in surge arresters can be listed as follows;

• Arc formation in the surge arrester, overheating, and fire risk
• The surge arrester not providing the desired lifespan
• Leakage current occurring in the surge arrester over time
• Occurrence of burning due to overload

One of the problems frequently encountered with surge arresters on the market is that due to the long distance between the MOV and the disconnector, when a heat increase occurs in the surge arrester, it is detected very slowly by the MOV. In Safetec technology, the electrodes are soldered onto the MOV.

However, there is a physical barrier between the MOV and the electrodes. The existing rotating disk reacts in less than 1 second, ensuring the safe disconnection of the MOV from the system in the surge arrester. Thus, the MOV is protected when an excessive impulse or energy comes to the surge arrester. In addition, this physical barrier prevents the arc event that occurs especially in DC surge arresters.

You can understand the patented Safetec technology much better from the image below. You can see the gas discharge tube, current limiter, and MOV. When an impulse comes, it is first dampened by the GDT. The current limiter prevents the MOV from being damaged in strong impulses. Thus, the surge arrester works healthily for a much longer time.

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. Especially with the PROBLOC series of Safetec technology, factories, power generation plants, solar energy projects, hospitals, and flammable/explosive facilities experience the confidence of long-term protection. As the Lightning Protection Center, your systems are now safer with ISKRA – RAYCAP LV surge arrester systems, for which we are the country representative. With the training received by our expert application team in Germany, Raycap Approved Application Guarantee and Insurance are offered to our customers in turnkey applications.

Contact YILKOMER engineers for detailed information and free survey.

You can see the advantages of SafeTec technology from our video below.