INSTALLING A SHOWER

[JeffGarry]

I want to install a new shower unit (Mira Sport Max 10.8kW) Can anyone advise me about uprating the consumer units' MCB (Crabtree Starbreaker). After reading some info it sounds as if I am required to fit an RCBO (50 amps) is this a simple task or can I getaway with uprating the existing MCB from 40 to 50 amps? Also I notice on RCBO's there is wiring to connect, does this require an expert? Finally, if the existing cable is only 10mm2 & 16mm2 is required, can I getawy with 10mm2 to run a 10.8 amps shower, or is it too risky? Thank you all.

 

[ban-all-sheds]

I want to install a new shower unit (Mira Sport Max 10.8kW) Can anyone advise me about uprating the consumer units' MCB (Crabtree Starbreaker). After reading some info it sounds as if I am required to fit an RCBO (50 amps) is this a simple task or can I getaway with uprating the existing MCB from 40 to 50 amps?

Is the section of the CU where the MCB would go RCD protected?

If not you'll need an RCBO.

Also I notice on RCBO's there is wiring to connect, does this require an expert?

There's wiring to connect to MCBs as well - not sure what your concern is?

Finally, if the existing cable is only 10mm2 & 16mm2 is required, can I getawy with 10mm2 to run a 10.8 amps shower, or is it too risky?

• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  

You should also read this: //www.diynot.com/wiki/electrics:part-p

 

[JeffGarry]

Yes I think it does. Thanks.

 

[Adam_151]

If you post a picture of the DB, we will be able to confirm whether the way supplying the shower is rcd protected or not

 

[Taylortwocities]

Do you think the existing cable is big enough? How have you measured the size of the conductors???

 

[JeffGarry]

Consumer unit. I have added pics.

 

[ban-all-sheds]

What about it?

 

[Taylortwocities]

Consumer unit. I have added pics.

No you haven't. But I'll do it for you View media item 28967
There....

So the shower is on the RCD side of the board. So far, so good.

Now, how have you measured the size of the conductors in the cable feeding the shower?? I will bet they are 6mm² so 40A will the largest cb you can have on that sized cable.

 

[JeffGarry]

Haven't measured the size of the conductors feeding the shower; please advise TTC. Thanks for your patients TTC.

 

[JeffGarry]

6mm has a solid earth 10mm has stranded. This cable has a solid.

 

[JeffGarry]

Untitled

• JeffGarry
• 12 Dec 2010
• 1

 

[ELZ4742]

that doesnt look like 10mm to me could be 6mm or even 4mm! job to know... are there no markings on the outer sheath of the cable?

 

[ban-all-sheds]

Jeff - you should add this to your reading list:

//www.diynot.com/wiki/electrics:flatpvccables

 

[JeffGarry]

It will require a new cable 10mm. I will leave it to the experts. Thanx for your help & advise.

 

[JeffGarry]

If I installed a 10.8kW electric shower with 6mm2 cable instead of the correct size 10mm2 & the correct loading MCB, is it a dead cert the cable will overheat & burn the house down? How easy is it to chase the existing cable (6mm2 with the correct size (16mm2). The property is a newish build 10 years old Bellway; would this be a bu**er to do, or should I leave the whole job to an expert? Thanx.