How good are you at telling the difference?
How good are you at telling the difference?
Above I referred to the installation instructions for EVSE made in Norway, which has a choice of two earth terminals for TT/TN-S or alternatively TN-C-S.
It appears that earthing as we know it is a bit of a novelty in Norway with an earthed neutral.
Here is a description of the Norwegian distribution network installation arrangements:
These are mainly two different types of power grids.
IT (Isolated Terra) is found in approximately 75 per cent of in Norway, and consists of either 1-phase (2 conductors) or 3-phase (3 conductors) plus earth (PE). There is 230V between each of the conductors and the neutral point of the transformer is not earthed, but is protected with a spark gap between neutral point and earth. Thus, there is no so-called zero conductor. To convert from IT to TN, a transformer must be used.
TN (Terra neutral) is used in almost all of Europe, and around 25 per cent of Norwegian electricity subscribers have this. TN consists of four conductors (three phase conductors and one neutral conductor) plus earth (PE). This means that you can extract 230V between each of each phase conductor and neutral conductor, and you get 400V between each phase conductor.
Above I referred to the installation instructions for EVSE made in Norway, which has a choice of two earth terminals for TT/TN-S or alternatively TN-C-S.
It appears that earthing as we know it is a bit of a novelty in Norway with an earthed neutral.
Here is a description of the Norwegian distribution network installation arrangements:
These are mainly two different types of power grids.
IT (Isolated Terra) is found in approximately 75 per cent of in Norway, and consists of either 1-phase (2 conductors) or 3-phase (3 conductors) plus earth (PE). There is 230V between each of the conductors and the neutral point of the transformer is not earthed, but is protected with a spark gap between neutral point and earth. Thus, there is no so-called zero conductor. To convert from IT to TN, a transformer must be used.
TN (Terra neutral) is used in almost all of Europe, and around 25 per cent of Norwegian electricity subscribers have this. TN consists of four conductors (three phase conductors and one neutral conductor) plus earth (PE). This means that you can extract 230V between each of each phase conductor and neutral conductor, and you get 400V between each phase conductor.
Which then gives some interesting wiring instructions for the Norwegian Zaptec EVSE.
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