Earthing System - Comparison of Earthing Systems

Comparison of Earthing Systems

TT IT TN-S TN-C TN-C-S
Earth fault loop impedance High Highest Low Low Low
RCD preferred? Yes No Yes No No
Need earth electrode at site? Yes Yes No No No
PE conductor cost Low Low Highest Least High
Risk of broken neutral No No No Highest High
Safety Safe Less Safe Safest Least Safe Safe
Electromagnetic interference Least Least Low High Low
Safety risks High loop impedance (step voltages) Double fault, overvoltage None Broken neutral Broken neutral
Advantages Safe and reliable Continuity of operation, cost Safest Cost Safety and cost

Read more about this topic:  Earthing System

Famous quotes containing the words comparison and/or systems:

    “Intolerance respecting other people’s religion is toleration itself in comparison with intolerance respecting other people’s art.”
    —Wallace Stevens (1879–1955)

    “What avails it that you are a Christian, if you are not purer than the heathen, if you deny yourself no more, if you are not more religious? I know of many systems of religion esteemed heathenish whose precepts fill the reader with shame, and provoke him to new endeavors, though it be to the performance of rites merely.”
    —Henry David Thoreau (1817–1862)