Why Should Only Type 1 (Class B) Surge Arresters Not Be Used in Main Switchboards?

In protection against lightning and sudden overvoltage impulses, internal lightning protection, i.e., LV surge arrester systems, is of critical importance. At this point, placing our LV surge arresters in a cascaded manner throughout the facility is as important as choosing the right product. One of the mistakes generally made is selecting products that only provide lightning protection instead of combined products in main panels. To briefly recall;

• Type 1 Class B Surge Arrester: Lightning impulse protection 10/350 waveform
• Type 2 Class C Surge Arrester: Grid impulse protection 8/20 waveform
• Type 3 Class D Surge Arrester: Protection of sensitive systems

In case we use only a Type 1 Class B product in our main panels, while our main panel remains unprotected against grid impulses, our entire facility will also remain unprotected against grid impulses that may come from the main panel and spread throughout the facility. Because we will not have the opportunity to lower the Up level sufficiently for the 8/20 waveform. In another negative situation, if there is not enough distance between the main panel and the sub-panel, the Type 2 surge arrester (25 ns Type 2 arrester, 100 ns Type 1 arrester), whose response time is much shorter than the Type 1 product used in the main panel, will activate in case of a lightning impulse, which may cause the panel to burn along with itself. To prevent this situation, it would be more correct to prefer combined surge arresters in our main panels.

Again, if your main panel feeds sensitive electronic systems such as PLC, automation, and drives, using only a Type 1 main panel surge arrester will not be enough to lower the protection level Up and protect these devices. Therefore, as Yılkomer, we recommend using Type 1+2+3 low voltage surge arresters in main panels in facilities such as factories where sensitive systems are located.