Installing RCCD and MCB for shower HELP!!

[Waterdude]

Hi i have an RCCD to install for my shower but it did not come with a wiring diagram. If anyone could shed light on what goes where i would be much obliged.

On the unit this is replacing there is the red/black/earth from the main consumer unit and the same coloured wires going to the shower unit.

thanks in advance for any replies.

 

[kevindgas]

if you are having to ask, i would get someone in to do it!!

it shouldn't cost that much to have it changed and tested, we would charge around £70 but your a tad out of our area

 

[holmslaw]

..

 

[riveralt]

What size is the shower kw?
What size are the cables mm?
What size MCB and cables are required by the Shower Manufacturer.

When you have worked that out - and ensured that you have the correct size cables for the enrvironment and MCB then.

You should have a buzz bar linking the RCD/Switch to the MCB. This is normally positioned at the bottom. It looks from your photo as if the Neutral is already set to the terminal bar on the right. The terminal bar on the left can be used as the earth(cpc).

Firstly, cables from consumer unit. The red cable goes into the top of the RCD marked L. The black cable goes to the neutral top of RCD and the cpc goes to the earth bar.

Then your correctly size shower cables go - brown/red to the top of the 50Amp MCB. The blue/black goes to the neutral bar and the cpc to the earth bar.

It is more than likely that the MCB is too big for the cable by the way.

I'm preety certain this comes within Part P in England not sure of the procedure where you are.

 

[ban-all-sheds]

Agree with both the above.

No way is that cable big enough for the shower you are fitting, and no way are you competent to be doing this work.

• http://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/Book/5.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm[/list]
  Consider yourself lucky that you don't have a clue how MCBs and RCDs are wired, or you might have just plunged in and built yourself a death trap.
  
  Please get an electrician.

 

[Waterdude]

Hi thanks for all the replies. Im in Scotland way up north, we have only just discovered electrickery.

The unit was bought specifically for a 9.5kw shower unit. It comes labeled as so from the manufacturer. Cables from the consumer unit are 10mm squared. These were supplying the former shower unit.

The shower requires a 30Ma RCD. And a 40 Amp fuse.

The MCB i have is 50amps, should i downgrade this to a 40amp MCB?

Wired as so? :

Thanks Stu.

 

[aptsys]

Oh dear

 

[Waterdude]

@BAS i came here for advice not a lecture.

 

[holmslaw]

..

 

[Waterdude]

Cor, you must have to be a F*****g rocket scientist to be a sparky. Us laymen wont be able to get to grips with it. Ask a simple question............................ its a good job you are not teachers "excuse me sir how do i solve this equation?" "shut up Jones, call the maths dept at Cambridge university".

I need to change the engine in my car........oooh better leave that to a mechanic there is no way you will be able to do that so we are not even going to help you.

Thanks Chaps, only one out of four provided any assistance whatso!

 

[ebee]

3 out of 4 tried to save you from yourself.

Do not build any rockets

 

[Waterdude]

Does anyone know the title of this website?

 

[ban-all-sheds]

@BAS i came here for advice not a lecture.

This is good advice:

"Agree with both the above.

No way is that cable big enough for the shower you are fitting, and no way are you competent to be doing this work."

This is good advice - how on earth do you think you can tackle this job without knowing and understanding these things?:

• http://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/Book/5.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm[/list]
  
  This is good advice:
  
  "Consider yourself lucky that you don't have a clue how MCBs and RCDs are wired, or you might have just plunged in and built yourself a death trap.
  
  Please get an electrician."

 

[ban-all-sheds]

Cables from the consumer unit are 10mm squared.

Gotta say they don't look it.

View media item 33918 View media item 33919
Why would somebody have used 10mm² on that old switchfuse?

What installation method applies to them?

Have you done the IR, continuity and EFLI tests on the circuit yet?

The MCB i have is 50amps, should i downgrade this to a 40amp MCB?

How much current will the shower draw?

 

[ban-all-sheds]

Cor, you must have to be a F*****g rocket scientist to be a sparky.

Not so.

Us laymen wont be able to get to grips with it.

Have you tried?

• http://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/Book/5.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm[/list]
  

  Ask a simple question............................

  The fact that you think it's a simple question, and/or that you think that's the only question you need to ask, just shows that you don't appreciate the complexities of the job.
  
  
  

  Thanks Chaps, only one out of four provided any assistance whatso!

  I provided this assistance:
  • http://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/Book/5.3.1.htm
    
    
  • http://www.tlc-direct.co.uk/Book/4.3.11.htm
    
    
  • http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
    
    
  • http://www.tlc-direct.co.uk/Book/8.1.1.htm[/list]
    Why do you think you don't have to do this properly?