How would you explain how PME works?

[davy_owen_88]

Here's one for a N-E fault caused by a misplaced (and unbelievably huge) nail. Here you just explain that the current will be shared between the neutral and earth conductor depending on resistances (but will be pretty much equal because they share the same route/cable).

 

[Adam_151]

Just explain that the RCD watches what goes through the phase and the neutral to ensure they match and that nothing is going anywhere else that could be electrocuting someone, if a fault gives some of the electrons another path to the PEN conductor, then they are not going where they should and the RCD can't see them and sees electrons going missing so trips out. Also explain that the more congested the neutral conductor, the more electrons that are going to take the alternative route (true as its the volt drop on the neutral between the intake and the fault that creates the P.D. to drive a current through the fault and cpc)

 

[securespark]

I can't keep up. Time I was

Moi, aussi!

But I have now got it, chaps! Thanks.
I know in principal what happens, but am not very good at trying to convert that into something understandable...

I was halfway there, but I have had a long day with lots of driving.

 

[ebee]

An RCD is not looking for a PD between N & E but a difference in current between Ph & N

 

[securespark]

Suddenly the dark skies clear, the sun comes out & the birds begin to sing...