Cable 9.5 kw Shower

[steph57]

Hello,
Our old 9.5 kw Triton shower has died beyond repair and we were thinking about replacing it with a 9.5 kw Aqualisa Aquastyle.
The shower cable is 6mm and runs openly through the ventilated roof space at the edge of our dormer bungalow and then up the un-insulated internal wall to the shower. As far as we can see from the Aqualisa installation guide 6mm cable is OK as long as it runs in open and venitilated spaces or un-insulated walls which ours does. However, we have been advised that nonetheless we really should change to 10mm cable or drop down to a 8.5 kw shower but we suspect that this advice is being over cautious as the current shower is 9.5 KW with no sign of any problems with the cable, our house wiring was inspected and certified a few months ago.
We will be buying the shower but it will be fittted by our local plumber, are we OK to go ahead and buy the 9.5 kw version to replace our existing 9.5 kw shower or should we go down the cautious route and drop to an 8.5 kw shower and risk a rather more poor shower performance?
Thank you.

 

[riveralt]

Follow the manufacturers instructions.
http://www.aqualisa.co.uk/aqualisa/files/09/091b3825-09f5-44f2-a9c7-4866a4291331.pdf
Which state that they are happy with 6mm² T&E cable is fine for the 9.5kw shower.
However, also note that they require additional RCD protection for the shower circuit.
10mm² T&E does give you greater flexibility though.

 

[EFLImpudence]

Some curious wording there, riveralt.

Why would they not be 'happy with' 6mm² clipped direct for 9.5kW @ 240V, 39.6A (8.7kW, 38A @ 230V) .

Could you explain why the manufacturer is 'not happy with' 6mm² cable clipped direct for 10.5kW @ 240V which they state correctly is 43.8A (9.7kW, 41.92A @ 230V)?

(For the OP, the current carrying capacity of 6mm² clipped direct is 47A.)


Why does the OP require any flexibility assuming the amount of work that would be involved?

 

[riveralt]

Seems the grammar police are 'unhappy' with my happy. Probably unhappy with my fine as well -

 

[JohnW2]

Seems the grammar police are 'unhappy' with my happy. Probably unhappy with my fine as well -

I don't think it was anything to do with grammar - it was more the apparent implication that (under other circumstances), manufacturer's instructions might somehow 'over-ride' BS7671 as regards what cable size was required for a particular load. If (as was the case) the cable is adequate per BS7671, I reckon that would mean it is adequate, regardless of what the manufacturer might say (or 'be happy' with!).

Kind Regards, John

 

[steph57]

Thank you for this useful information, Thanks