[magicalhippo]

I'm no expert, but here in Norway we predominantly have IT systems[1], though new installations are mainly TN.

In the IT systems, the protective earth is not bonded to the neutral. Thus in case of a fault, the protective earth should be low impedance to ground so that the circuit breakers trip. At least that's my understanding.

[1]: https://aktif.net/en/types-of-earthing-systems/#IT_System

[rainbowzootsuit]

Thanks for the link. I don't know all the symbology there so it will take some reading up.