B+C Class (Type 1+2) 100 kA Low Voltage Surge Protector

In our country, when surge protection devices are mentioned, the first definition that comes to mind and the first product encountered in specifications is the 100 kA Class B+C; according to IEC standards, this is referred to as a Type 1+2 100 kA LV surge arrester. This product, which is considered the primary protection for the Low Voltage Main Distribution Panel in our country, is examined in detail in this article. First of all, we would like to state that within the scope of IEC 62305, kiloampere levels are determined by performing a risk analysis and considering the location where the products will be used. It is not mandatory to use this 100 kA product in every region and at every point. However, as engineers, we tend to be cautious, and therefore we prefer surge arresters with a protection capacity of 100 kiloamperes, which are considered among the most powerful products on the market. The definition of 100 kA arises from the theory that the maximum lightning current is 200 kA, the soil structure provides a 50% attenuation capacity, and the remaining discharge of 100 kA is directed to our panel via four conductors.

B+C Class Surge Arrester

In fact, many LV surge arresters sold as 100 kA on the market do not provide 100 kiloamperes of protection per phase. They typically offer a maximum of 50 kA protection per phase. However, there are also products that truly meet the specification requirement and provide 100 kiloamperes of protection per phase. Given the sensitivity of this issue, we can select products rated at 100 kA per phase. When we closely examine the characteristic curves, a 100 kA B+C class product must have top-level test characteristics on both 10/350 µs and 8/20 µs waveforms. Although test characteristics differ for per-phase and three-phase configurations, many products are tested at 50 kA and 100 kA levels. When we look at the technologies used in 100 kA products, Spark Gap (carbon ring) technologies stand out. These products have higher durability compared to varistor-based technologies and are ideal for use in main distribution panels. However, spark gap technology products have slower response times, with an average value of around 100 nanoseconds. Varistor-based products, although more susceptible to damage, detect surges at approximately four times the speed. Nevertheless, cartridge-type models that are easily damaged may not always be preferred. For this reason, new-generation products utilize both the speed of varistors and the strength of gas discharge tubes, offering fast and durable solutions to the market. Establishing the concept of 100 kiloamperes per phase and preferring products that combine varistor and gas discharge tube technologies present the most effective solution for protection starting from the Main Distribution Panel.

However, according to IEC standards, protecting only the main incoming panel is not sufficient. Important sub-distribution panels, automation systems, telecom lines, camera systems, measurement, and control systems can also be protected with coordinated, multi-stage protection devices. By coordinating products according to their Up levels, all systems within the facility can be protected against lightning and utility surges. Proper product selection requires accurate site surveys, system analysis, and correct planning during implementation. Once these steps are completed, the facility can continue operating safely and sustainably.

As the Lightning Protection Center , we keep the latest technology 100 kA B+C Class Low Voltage Surge Arresters in stock. In addition, we provide product selection, site survey, and installation services with our expert engineering team. For technical details and inquiries, you can contact us via the Lightning Protection Hotline at +90 212 210 2728.