consumer box question ... HELP!!

[robdavis]

I have a 9.5Kw shower installed but the fuse in my consumer box to the shower is a 32Amp I would like to change the amp to a 45A fuse (which is recommened by the shower manufacturer)

however my question is
I have an Ln6180 fuse box that I suspect is only an 80Amp rated, The fuses in my box read 32A,6A,16A,32A,32A can I take out the 32A fuse that is assigned to the shower unit and replace it with the 45A ? so it will read 45A,6A,16A,32A,32A or will this be overloading? as i read it at the moment I am already overloading at 118A through an 80A CU or am I wrong?.
or does the rating mean 80A maximum per fuse?

The shower was installed by a professional and he was supposed to come back with the fuse and replace it but never has.

 

[ban-all-sheds]

1) You've got MCBs, not fuses.

2) You must never just put a higher rated one in without confirming that the cable, as installed, has sufficient current carrying capacity.

• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  

3) The LN6180 is a 100mA RCD, which is not what the shower requires - the manufacturer will have specified a 30mA one.

4) The guy who installed the shower may have been professional in the sense that he charged you money, but that would have been the only sense - I hope his transport left you some food for your roses.

5) You need to get a proper electrician.

 

[LearningSpark]

You can't just change the mcb without first identifying what size cable you have, how it has been installed and measured the EFLI of the circuit. Get your professional back to put in the correct size mcb as stated in the MI and retest your circuit for you. If you change the mcb yourself then you will alter the circuit characteristics and the certificates he issued will no longer be valid and probably nor will your home insurance.

 

[ban-all-sheds]

... the certificates he issued ...

 

[LearningSpark]

B-A-S. You'll be telling me next the "professional" who installed the shower wasn't actually an electrician!

 

[robdavis]

Well he is an Electrician to 17th edition (well so he said my fault I never checked) he did check the cable was the right type, I was there when he did it , Infact I did go into the loft and checked the cable before I asked for quotes on the job cos I didn't realy want to buy a shower then have to fork out for my home rewired. ( I work for an Electrical cable distributor so I kinda know what to look for and what size I need , But dont have the qualifications to start messing around with installing it).

When I said fuses I meant MCB
I did today finally manage to get hold of the chap who installed my shower He said he will be coming around but I still don't hold hope.
I will definetly be asking him some tough questions when he turns up
anything else I should quiz him about?
However I have asked him about the certificate and he says there has not been one issued yet as the job isn't completed.

 

[LearningSpark]

I hope you didn't pay him then if the job isn't completed yet.

 

[333rocky333]

If you have the older LN range mk board then your unlikely to get a 45a mcb anyway, there obsolete, possibly get a second hand one maybe

 

[ban-all-sheds]

I hope you didn't pay him then if the job isn't completed yet.

And I hope the circuit's not been energised.

So - let's see.

- Wrong rating MCB

- Wrong rating RCD

- No certificate

- Guy gone AWOL

It's not looking good, Rob.

What size cable is it?