Broken neutral

First PEN conductor is not the same as Neutral, it is a Protective Earth and Natural.
Not quite sure what you mean, no machines would work at the end user if the PEN conductor to the incoming central was broken so it's quite self indicating, since most of them need a neutral to work.
Unless you have a facility that only consists of direct connected 3-phase motors and nothing else.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

NO idea myself, but this might help?

PEN seems to be Protective Earth and Neutral -
Did you look?


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