On Sat, 17 Jan 2004, ripper wrote:

You are wrong, P=V*I according to ohms law.
Therefore, I= P/V
Power remains constant @ 9.5 kW

That's where you are wrong, power does not remain constant.
There are various means for modulating power to electric heating elements
but electric showers do not generally incorporate anything more
sophisticated than the ability to switch either or both of a pair of
heating elements on.

Many heating appliances these days have rating plates showing the current
consumption / power output for different input voltage e.g. 230v and 240v.
In all cases you will find the power output (and current) higher for a
higher input voltage.

--
Alistair Riddell - BOFH
Microsoft - because god hates us