The earth fault protection and protective electric devices of TT and TNsystem and the application conditions were analyzed.
分析了TT和TN系统的接地故障保护和保护电器及其应用条件。
2
The use of PE line in TNsystem and TT system is analyzed, and the characteristics of lighting return circuit in residence and the advantages of adding PE line are discussed.
对PE线在TN系统与TT系统中的作用进行了分析，讨论了住宅内照明回路的特点及增加PE线后的优点。
3
This paper simply mentions the function of TN-C system neuter line, the circuit analysis of two single-phase circuit in common the neuter line.