I reckon someone is getting confused between normal overcurrent 
     breakers and RCD's/ELCB's (Earth Leakage Current Breakers or Ground 
     Fault Detectors in the US) which are used on portable tools, 
     lawnmowers etc. On ELCB's, a coil and some electronic gubbins, 
     monitors the difference between the current in the phase and the 
     current in the neutral. If this is over a nominal figure (roughly 
     30mA) this means that some current is flowing to earth, possibly via a 
     human:-( and the supply is removed from the load double quick. As 
     usual Mr. Quick is completely right and it sounds like Ed's mate is 
     not in possession of all the facts.