Electrical – Why do EU electrical sockets/plugs have two pins for grounding

europeangroundgroundingplugsocket

Inside a plug there is one grounding wire, while the socket has two grounding pins. I know that the wire splits into two, but why? As the wiring inside the wall is supposed to be the same between different types, I assume it is just a design decision, however does this mean that in such design I could theoretically have one broken pin for grounding and successfully ground a plugged device only by using one pin on the socket?

Best Answer

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Figure 1. Schuko sockets. (Image source: Bran.)

If you are referring to these sockets the dual earth pins give balance pressure on the plug which would otherwise be forced to upwards or downwards making insertion difficult and possibly affecting the contact of the L and N pins in their sockets.

... does this mean that in such design I could theoretically have one broken pin for grounding and successfully ground a plugged device only by using one pin on the socket?

Yes, but it is most likely that the two contacts are stamped out of one sheet of metal and there are no joints so fracture or breakage is unlikely.