GB wrote:

Harry Bloomfield wrote:

All supplies are 415v 3 phase, which is 415v measured from any phase
to any other phase. The 240v is derived by connecting from any one of
those phases to a Neutral wire which is effectively the ground/ earth
connection at the sub-station. Basically, the idea is that all of the
240v supplies should be equally balanced loads on each phase, so that
no current flows down the neutral. Now if someone removes that bit of
bus-bar which connects it to ground and should the 240v supplies
happen to be badly balanced, then that 240v can rise upto the phase
to phase voltage of 415v. So instead of the 240v a domestic consumer
might get normally, they get 415v instead.

Is there a reasonable chance that something would burn out and (hopefully)
trip the mains switch?

We had a copier burn out at work one night, due to some
ill-executed site electrical maintenance. Luckily the smoke was
spotted before it took the building with it.

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.