
The Importance of IEC 62305 Standard in Ministry of Labor Inspections
18 October 2015Protection of KNX and DALI Lines Against Lightning and Overvoltage Surges
24 October 2015Internal lightning surge protection (parafudr) systems are an important part of protecting against lightning and overvoltage. However, what we often see in facilities is either parafudr systems not being used at all, or being used incompletely or incorrectly. In this article, we will discuss the features a parafudr should have for your facility.
1- Damping Technology
Parafudrs usually perform damping using either varistor technology or spark gap technology. Varistor technology absorbs the surge quickly, but is vulnerable to high surges or prolonged impulses. Therefore, its cartridges may need frequent replacement. In telecom, solar, wind, etc., facilities, frequent cartridge replacement may not be feasible due to accessibility challenges. Spark gap technology, on the other hand, provides unlimited damping but may miss some surges due to slower response. To address these issues, parafudrs with VG technology that combines both varistor and spark gap technologies should be used.
2- Increased Temporary and Overvoltage Resistance
Parafudrs have a certain continuous operating voltage. However, they may occasionally be exposed to high voltages from the network or facility. Therefore, the operating range should be wide and the resistance to temporary surges should be high.
3- High Surge Protection While Maintaining Low Protection Level (Up)
While parafudr systems should have high Imax and Iimp surge withstand ratings, the voltage level (Up) that will reduce the system voltage should be low.
4- Durability and Reliability
All components of parafudrs should be resistant to possible high current surges. Especially power and control circuits should be manufactured to withstand these surges. This increases the lifespan of the parafudr.

5- Status Signal and Safe Connection Notification
For a more stable and controlled protection system, the parafudr should be safely connected to the system and its status continuously monitored. This ensures safe and efficient maintenance.
6- Staged Protection and Coordination
For complete and correct protection, parafudrs should be selected and applied in stages. Parafudrs with VG technology allow staged protection without issues like distance or additional parafudrs.





