Hi!

I've on occasion wondered what would happen if we lost the neutral line.

(speaking from a 110V perspective as I'm in the US where power is delivered
as 2x110 volt hot leads with one neutral)

The voltage between the two fluctuates wildly, that's what. The more heavily
loaded of the two will have a voltage drop while the lightly loaded one goes
up.

CRT computer monitors get the jitters even when things are relatively
normal. I don't know why this is. Damage can occur to devices when they get
nailed with high voltage.

It won't be a huge issue up to a point for simple devices, or those with
autoranging power supplies that may try to compensate. Everything else will
suffer--motors, transformer type power supplies, etc...and your electrican
*should* know that. A fire could start depending upon how badly something
reacts to the over or under voltage.

William (had it happen here some years ago - one TV and a few surge
protectors got burnt. Curiously, the TV was not completely dead afterwards,
just temperamental about turning on when warm.)