mira sport 10.8 question

Billy Reid · Nov 17, 2014

Hi, had a mira sport 10.8 kw shower fitted 10 years ago and all new cable installed.
Just had a new mira 10.8 kw shower this week to replace old one. Just a case of swapping like for like.
Here's my question though. A bit of cable was left and it is 6mm. Mira says it needs to be 10mm?
Anyone help? I
Would have thought sparky fitting shower 10 years ago and fitting new cable would have used 10mm? Or was 6mm standard back then?

dave274 · Nov 17, 2014

it needs to be 10mm. I would imagine its got a 50a mcb and the max for 6mm is 47a. plus the manufacturer says 10mm.

Guest77 · Nov 17, 2014

It will pull 46.44 amps at 230 volt, so that said whats your thinking?

Billy Reid · Nov 17, 2014

Thanks. I guessed it needed 10mm but don't understand why 10mm wasn't used when fitting original shower as all cable was replaced.
I'm not electricity minded and font know ow what 50a mob is though. Sorry.
Breaker switch is Wylex .has B40 on it and 3000.
Sorry don't know much. Guess I will have to find a sparky to rewire with 10mm .

Simonslimline · Nov 17, 2014

Billy Reid said:
Thanks. I guessed it needed 10mm but don't understand why 10mm wasn't used when fitting original shower as all cable was replaced.
I'm not electricity minded and font know ow what 50a mob is though. Sorry.
Breaker switch is Wylex .has B40 on it and 3000.
Sorry don't know much. Guess I will have to find a sparky to rewire with 10mm .

Cheaper to get a less powerful shower surely!

Does it really need to be 10.8Kw. Mine is 7.5Kw and still gets me nice and clean.

Billy Reid · Nov 17, 2014

Wouldn't be a problem if original sparky fitted 10mm instead of 6mm though.
So if I leave it at 6mm cable am I right in thinking it would only run as 9.8 kw shower?

driverman · Nov 17, 2014

Was the first 10.8kw shower the original shower unit on that circuit was installed? Was there another shower unit before the 10.8kw? Is it easy to rewire. If not buy a smaller rated shower to suit your cable. Don't forget if installing a new circuit, an RCD will be required

Billy Reid · Nov 17, 2014

driverman said:
Was the first 10.8kw shower the original shower unit on that circuit was installed? Was there another shower unit before the 10.8kw? Is it easy to rewire. If not buy a smaller rated shower to suit your cable. Don't forget if installing a new circuit, an RCD will be required

I had a shower before get to grips 10.8 fitted. Maybe 7.5 but had bathroom done up and chose 10.8 . Guy fitting the 10.8 said it would need new cable to facilitate the 10.8. Font know why he used 6mm though and wouldn't have found out either if we didn't replace shower.
The previous 10.8 shower has been running off 6mm for 10 years!!