correct shower rating??

ukpablo · Nov 17, 2010

ok, without visiting the premisies and without testing the actual voltage, what is the score with this specific shower.

existing set-up

6mm T&E
40A mcb with rcd protection
old shower was 8.7kw load / 9.5 kw supply voltage??? so instructions read!

new shower, still in box

instructions state:

230 v 50hz etc 9.5KW (nominal voltage 240V)
8.8KW (nominal voltage 230V)

Both under 40A with calculation, so question is do i need to measure actual voltage, and what is the pwr the shower is rated at??????????? is it somewhere between??
Also i know 9.6KW should be 10mm T&E so is existing ok? i believe it is but that is why i am asking for some form of clarification.

SirKit Breaker · Nov 17, 2010

Take all your calculations whether it be a shower or any other appliance at 230v. This is the voltage at which we are now working towards to harmonise us again with europe. I would go with worst case scenario, and work on 9.5kw @ 230v.

Cheers.........Howard

sjm · Nov 19, 2010

I believe the answer is that the ratings are 8.8Kw at 230 volts or 9.5Kw at 240 volts. This lower power usage at lower volts appears to be the way that voltage optimisers save power usage and therefore money. As for 6mm cable on 40 amp breaker, how long is the run and what installation method is used?

nickblake · Nov 19, 2010

As howard has said always work on the worst case senario whether a shower or heater or what ever load

telectrix · Nov 19, 2010

personally, i would fit the shower to existing 6mm. measure current drawn with clamp meter, (shower on highest heat) and measure volt drop, if any. allow for de-rating cable depending on installation. as long as regs. are satisfied, OK. Highest calculated current is 41.3A, but i doubt if it will pull 40. most showers are over rated anyway.

davelerave · Nov 20, 2010

sjm said:
I believe the answer is that the ratings are 8.8Kw at 230 volts or 9.5Kw at 240 volts. This lower power usage at lower volts appears to be the way that voltage optimisers save power usage and therefore money. As for 6mm cable on 40 amp breaker, how long is the run and what installation method is used?

ya-they're marked 8.5kw/9.5kw 230v/240v or thereabouts

there'll be a few extra amps at 240

most people are looking for the extra kilowatt or 2

for the instantaneous shower( not less)

you'd save money with the voltage regulation on the instantaneous loads alright(a colder shower)but on kettles and other loads there'd be no saving only time wasted waiting for kettle to boil