Earthing neutral

But  isolation is very rarely fitted on a PE and that extract you posted does not mention it at all - actually switches and breakers are generally NOT permitted  in a PE, unless the phases are broken first ( same reason  the earth pin on a mains plug is longer than the other two. )

Actually the whole diagram is a bit simplified, as we almost never parallel sources without some means of isolation, and gross over current protection,  to detect large fault currents - it is perhaps OK with 2 identical transformers on the same HV feed, but in many cases like genset and mains supplies you cannot even assume a particular phase relationship.


When you say you would earth at TX and gear, are you meaning to terra-firma, as in an electrode into the ground at each location, or that you would connect to the HV earth ?

This depends on the type of fault that is possible, and if you are considering an HV-LV fault, and the rise of earth voltage this causes. On a genset that is not credible, but  a mid winding to frame fault is.

But  isolation is very rarely fitted on a PE and that extract you posted does not mention it at all - actually switches and breakers are generally NOT permitted  in a PE, unless the phases are broken first ( same reason  the earth pin on a mains plug is longer than the other two. )

Actually the whole diagram is a bit simplified, as we almost never parallel sources without some means of isolation, and gross over current protection,  to detect large fault currents - it is perhaps OK with 2 identical transformers on the same HV feed, but in many cases like genset and mains supplies you cannot even assume a particular phase relationship.


When you say you would earth at TX and gear, are you meaning to terra-firma, as in an electrode into the ground at each location, or that you would connect to the HV earth ?

This depends on the type of fault that is possible, and if you are considering an HV-LV fault, and the rise of earth voltage this causes. On a genset that is not credible, but  a mid winding to frame fault is.