Capstone - Earthing Flashcards
AS/NZS 3000 clause 5.1.3 states that the neutral in an MEN system is to be earthed at which point(s)?
1 - At the source of the supply
2 - At regular intervals throughout the system
3 - At each electrical installation connected to the system
Within an electrical installation, what is the earthing system connected to?
Exposed conductive parts of equipment
What is the IEC term used to describe the MEN system?
TN-C-S
In a TN-C-S system, where is the point of connection at ‘T’ and what is the part of the system that is connected?
Neutral point of the supply transformer, distribution system
In a TN-C-S system, where is the point of connection at ‘N’ and what is the part of the system that is connected?
At MEN connection, exposed conductive parts
In a TN-C-S system, what is meant by ‘C’?
Neutral and protective conductor functions are combined in a single conductor (the neutral conductor of the distribution system)
In a TN-C-S system, what is meant by ‘S’?
Protective conductor function separate from neutral - separate conductors within the installation
Where will there always be an MEN link, main earth, and earth electrode?
Main switchboard
Where will you always find a PEN conductor?
Upstream of an MEN link
What is a PEN conductor?
Protective Earth Neutral - single conductor that functions as both neutral and protective earth
What other systems are used (outside Australia) besides TN-C-S?
TNC, TNC-S, TNS, TT, IT
A structure containing a switchboard separated by an area of land from the structure containing the switchboard that supplies it is known as what?
Individual outbuilding
Any number of structured installed/built on the same foundation, sharing conductive metal roofing or conductive metal frames, with more than one electrical supply, separated by an area of land from another structure that contains the switchboard that supplies them is known as what?
Combined outbuilding
Outbuildings are required to be earthed in accordance with which AS/NZS 3000 clause?
5.4
Individual outbuildings may be earthed by either connecting to a PEN, or as a separate MEN installation - True or False?
True