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T-N-S or TN-C-S ???? Help pls.

MrFox

I have been asked to replace a consumer unit. All seems fine, and the incoming earth seems to be on the sheath of the incomer, so, TN-S. But, it says TN-C-S on the previous EICR. Did that spark make a mistake or is there something here I'm missing? Also, do we presume the Line and Neutral are in that cable going to the meter??? I hope so… Thx in advance.

b13f6e8ca4a8740403be79c8a45433ce-huge-tns_or_tncs.png
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    I would be extremely suspicious of this EICR, as the classification of this installation as TNC-S without further comment is clearly an error of a significant type. There is obviously no N-E link anywhere and there cannot be with the head type and cabling shown. Whilst we often discuss DNO practice here it does not change the apparent installation type that is observed. A further question, what is the Ze stated, it would measure as very close to zero in a TNC-S installation with the N-E link in the correct position, which is in the HEAD? The PSCC is not relevant to this point, only the Earth loop value in Ohms from the neutral to Earth for the installation.

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    I would be extremely suspicious of this EICR, as the classification of this installation as TNC-S without further comment is clearly an error of a significant type. There is obviously no N-E link anywhere and there cannot be with the head type and cabling shown. Whilst we often discuss DNO practice here it does not change the apparent installation type that is observed. A further question, what is the Ze stated, it would measure as very close to zero in a TNC-S installation with the N-E link in the correct position, which is in the HEAD? The PSCC is not relevant to this point, only the Earth loop value in Ohms from the neutral to Earth for the installation.

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