'commando' plugs
[(1) If the plug is half plugged into the wall, and there's a power surge etc causing current flowing through the earth, half insulated earth pin in this case is useful (the person wont get full blown shock if he/she is touching it).
(2) But, contradictingly, if there's a high current flowing through the earth and the pin is half-insulated with plastic, then the plastic will potentially melt and cause hazzard. May be that' why the earth should be full metal?
I believe (2) is likely to happen more than (1)...
(1) If the plug is half plugged into the wall, and there's a power surge etc causing current flowing through the earth, half insulated earth pin in this case is useful (the person wont get full blown shock if he/she is touching it).
Aside from the fact that it'd affect the phase pin equaly... and I'm sure you have never seen an insulation failure in an applicance melt a plug into a socket outlet by virtue of melted plastic on the pins.... ... logic tells you it just wouldn't happen, even given the higher resistance of brass compared to copper and the nearby contact resistance, the fault level needed to melt plastic off a 32mm² earth pin would have a similar effect on the circuit conductors!(2) But, contradictingly, if there's a high current flowing through the earth and the pin is half-insulated with plastic, then the plastic will potentially melt and cause hazzard. May be that' why the earth should be full metal?
Well (2) is just not going to happen in the real world...I believe (2) is likely to happen more than (1)...
'commando' plugs
Are those the ones that don't wear underwear?
This is also why the live pin is at the top - if L and N were at the top, as you say, a metal object could be dropped between them.Another reason live & neutral pins are insulated is that a 1p peice wedges nicely between the pins and a few years back there was a spate of incidents when some kids thought it would be funny to wedge pennys into the pins and watch people plug them in and go pop!
Just a little useless information for you.
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