Replacing Shower 8.5kW to 9.0kW

Tritont90

Looking into replacing a Triton T90XR with a Triton T90SR. 8.5kW to 9.0kW. Have a 40A MCB as advised but believe we have a 6mm cable, which I'm not sure is sufficient.

Is it LIKELY to be an straightforward swap or would it likely involve a cable upgrade?


Would really like the SR (silent) model but will go for another noisy 8.5kW if cables need to be changed.

Thanks all.

Sleeper12

Triton don't make any 8.5kw pumped electric showers anymore. I have replaced the 9kw element for an 8.5kw in situations where 6mm wasn't enough for the 9kw.
No one can say for sure without looking at job if 6mm is ok. The rule of thumb is that 6mm is ok up to 15 metres but this changes a lot depending on wall and attic insulation.
If you are getting a professional shower installation company or an electrician they will be able to advise you on the safest set up.
10mm is always the best option. I have this in my own home even though the run is less than 5 metres.
Don't forget it's possible to swap the 9kw for the 8kw element if all the else fails

Tritont90

Great info that thanks. Appreciated.
I guess there is no yes or no answer so I will have to get the electrician out twice.

I wouldn't think the 6mm is greater than 15 meters, the board is almost directly below the shower room. But then again I'm no electrician.


Didn't realise the 9kw element could be changed for an 8kw. If that's the case I can end up with the SR (silent version) either way. Is changing the element a big job?

Sleeper12

Tritont90 wrote:

Didn't realise the 9kw element could be changed for an 8kw. If that's the case I can end up with the SR (silent version) either way. Is changing the element a big job?

Sorry my mistake it's a 8.5kw element rather than a 8kw. Your electrician can swap the element at the time of installation

EHP

Sleeper12 wrote:

Triton don't make any 8.5kw pumped electric showers anymore. I have replaced the 9kw element for an 8.5kw in situations where 6mm wasn't enough for the 9kw. No one can say for sure without looking at job if 6mm is ok. The rule of thumb is that 6mm is ok up to 15 metres but this changes a lot depending on wall and attic insulation. If you are getting a professional shower installation company or an electrician they will be able to advise you on the safest set up. 10mm is always the best option. I have this in my own home even though the run is less than 5 metres. Don't forget it's possible to swap the 9kw for the 8kw element if all the else fails

Just to note changing to 8.5kw element doesn't necessarily mean that 6sq cable is OK for the shower. Depending on the way the cable is installed such as under insulation in the attic or in an insulated wall etc you may still need 10mm cable.
8.5kw shower at full load can draw almost 37 amps, no shower really draws full load so let's say 30 amps average over 10 meters laid in insulation 100mm or greater, that install would require 10mm cable to comply with regs. If you fit a new shower the Electrical side must be completed by a REC and the REC must issue you a cert. The same install with the cable clipped direct and not in insulation would be OK with 6mm cable.

brightspark

EHP wrote: »

8.5kw shower at full load can draw almost 37 amps, no shower really draws full load so let's say 30 amps average.

I am open to correction, but I thought showers were always at full load with the water flow rate determining the temperature? (Some I admit may have a low power option for use in summer when the incoming water is already warm)