l and earth
Rubbish. In most of Canada, it is manditory that the neutral be bonded to earth at only ONE point, the service entrance switch enclosure. From that point an earth conductor is connected to 2 ground rods and to any metallic piping system(s). Neutral failure is a not uncommon problem especially with overhead aluminum 'triplex' service drops. A seagull deficates on the bare aluminum neutral and it soon rots off leaving an open neutral condition. Ground rod to earth resistances of 5 ohms are not uncommon, so a 10A unbalance between 'phases' could give a 50V offset of the neutral.
Neil S.