This sketch might help explain what electure is saying.

The over-voltage resulting from an open neutral on a multi-wire circuit will depend on how well the load is balanced.

The sketch shows what I would consider an extreme case, and it definitely would cause damage.

In circuit A the voltages across the two loads are approximately equal because of the intact neutral conductor.(The line voltage drops are not calculated here).

With the neutral open (circuit B) the 10 ohm and 30 ohm loads are in series for a total of 40 ohms. There is a damaging overvoltage on the 30 ohm load, due to the unbalanced load. If the load were perfectly balanced, there would be no voltage difference.

[Linked Image from electric-ed.com]

Ed


[This message has been edited by electric-ed (edited 01-14-2003).]