Hakuhou
Trainee
S refers to the installation side, whereby the earth and neutral returns are “Separate” on this side.
The neutral and earth separate at the intake of the installation.
This was interesting. The PEN fault at neighbor 2 meant that their neutral was returning through their earth, into the metal services, into neighbor 1’s and then into neighbor 1’s earth-neutral link.
When neighbor 1 disconnected their earth neighbor 2’s electrics stopped, with the added drama of this energizing everything connected to the earth systems of both neighbors.
I’m still thinking about what kind of earth system it would be. I think that a TT that is connected back to a TN-C-S (e.g. via some metal pipe work that’s been earthed by both systems) is an extension of that TN-C-S.
After reading all this my question becomes, what happens if the earth electrode in what is intended to be a TT system connects/is not sufficiently insulated from the CNE.
The CNE is used by other installations (e.g. other houses) as part of their TN-C-S systems.
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