Earthing neutral

In the clip you have attached it is the section from either transformer to the point of junction that has to be treated as PEN.

From either point A via B to C . And from point C you could take both PE and an N  (not shown here ) to any loads if you need it.

So what do we mean by "treated like a PEN" -

1) sized to carry the full phase  current if required - seems reasonable, as in fault it may need to.

2) Double crimp or dual bolted joints as loss of connection is a serious matter - again reasonable - think what happens if there is a break on one side and not the other - in the lives you may put fuses or switches if required, and in the N after the PE separation, but not before.

In the clip you have attached it is the section from either transformer to the point of junction that has to be treated as PEN.

From either point A via B to C . And from point C you could take both PE and an N  (not shown here ) to any loads if you need it.

So what do we mean by "treated like a PEN" -

1) sized to carry the full phase  current if required - seems reasonable, as in fault it may need to.

2) Double crimp or dual bolted joints as loss of connection is a serious matter - again reasonable - think what happens if there is a break on one side and not the other - in the lives you may put fuses or switches if required, and in the N after the PE separation, but not before.