| Title |
Evaluation of the Protection Performance of TT and TN Systems for Low-Voltage Consumers Against Lightning Surges |
| Authors |
Kyu-Sun Lee ; Jong-Hyuk Choi ; Bok-Hee Lee |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2010.24.6.067 |
| Keywords |
Low Voltage Consumer ; TT System ; TN System ; Lightning Surge ; Equipotential Bonding |
| Abstract |
Most of domestic low-voltage consumers are supplied from the TN-C system of KEPCO, but their load installations have established according to the national statutory standard for electrical installations based on the TT system. In this work, to propose the proper system earthing arrangements of ensuring the protection of information-technology equipment against lightning surges, the protection performance of TT and TN systems against lightning surges was investigated. As a result, when lightning surge was injected to the neutral line of distribution system, the potential difference between the equipment earth terminal and neutral point of low-voltage mains in a TT system was significantly raised. The TT system is not advised due to the risk of damage to the sensitive computer equipment. Main equipotential bonding is an important requirement for protection of low-voltage installations against lightning surges. The TN system provides the best means to reduce the incoming lightning surges through the neutral line of low-voltage service systems. In addition, It is highly recommended to install the additional earthing at the service position of low-voltage consumers. |