I have one question. I'm designing a PCB which is a sort of smart switch (so, basically, you have one 230V input and one 230V output, where the output and the input share two wires, N and PE, and the circuit acts on the L. So basically something like this:
Now, the PE connection is not "functional" (the case is plastic, so no earth-connected-case is needed); it's just a connection between the input and output.
Now, my question. In my mind the connector layout should be L-PE-N. On a lot of appliances (for instance the SMPS in metal cage have L-N-PE-low voltage outputs).
I think the metal cage SMPS have PE between the two to act as a protection, and so I came to think that every layout is fine (provided that the required clearances are respected - BTW I'm using at least 4mm of clearance in the 230V area).
Am I right (so I can use the most functional layout) or you recommend some layouts?