"ripper" wrote in message
...
You are a little wrong here, the supply voltage is allowed to fluctuate
between +10% and -6%.
However, should your voltage be higher than the 230 Volts, the less
current
your load will draw.
This is a simple application of ohms law. The higher the voltage the less
current the load will draw.
That aside, as I said earlier - your MCB is too small. 45 Amps is the
correct size for this shower.

???
Since when did a shower have negative resistance!!!!!!

Volts=AMPS*RESISTANCE

Power=Volts*amps

If the resistance remains approximatly constant such as in the case of a
shower if the voltage goes up the current goes up P=(V*V)/R

In the very very special case of a swich mode powersupply the output power
and the input power is aprox constant regardless of supply voltage so ONLY
in this special case the volts go up and the amps go down.