Earthing systems and fault paths

What does the acronym TN-C-S represent in earthing arrangements?

• Terra Neutral Combined Separate

• Total Neutral Combined System

• Technical Neutral Current System

• Transformed Neutral Circuit Standard

In a TN-C-S earthing system, what is the path for fault current from the installation back to the transformer?

• Through a dedicated earth rod at the installation

• Down the neutral conductor, then back to the transformer's star point

• Through the outer sheathing of the supply cable

• Directly through the general mass of earth from the installation

Which component typically provides the separate earth in a TN-S earthing system?

• A dedicated earth rod installed at the property

• The outer sheathing of the supply cable

• The neutral conductor of the supply

• A connection to the metallic water supply pipes

Why are TT earthing systems considered less reliable for fault current dissipation compared to TN systems, often requiring additional protective measures?

• They have lower overall system impedance

• The neutral conductor is not earthed at the substation

• The fault current must travel through the ground, which has variable resistance

• They use a combined neutral and earth conductor