help needed

[rickus19]

Hi there, I recently enlarged my garden shed. I found that the electrical feed is a shower/cooker cable. This cable comes directly from my fusebox and supplies 1 double socket. I need to add 2 more sockets and wondered if anyone can tell me the easiest way to do this. Thx in advance Rickus

 

[ban-all-sheds]

I found that the electrical feed is a shower/cooker cable.

What do you mean by that?

This cable comes directly from my fusebox and supplies 1 double socket.

What's the rating of the fuse/MCB?

Is it RCD protected?

 

[rickus19]

I mean that a friend told me that its cable usually used for a shower/cooker....ie its very big. It is on a 30 amp fuse, I don't know what a RCD is sorry.

 

[PrenticeBoyofDerry]

Firstly: Although cable to electric showers are generally larger than those that supply the standard socket circuit, there is no such thing as shower cable. Cable is rated at it maximum current carrying capacity not by the application it will undertake.

It sounds like you have an existing circuit, that has possibly (confirmation required) has used 6.0mm2 T&E cable forming forming a radial circuit protected by a 30A fuse.

If that is the case, you can extend this circuit to add additional socket outlets, 4.00mm2 T&E cable will be required to continue the circuit but the sockets must have 30mA RCD protection.
This is a unit that detects earth leakage and is a requirement.
http://en.wikipedia.org/wiki/Residual-current_device

It is desired that any addition made, is compliant to BS7671 and Part P of the building regulations, this would include the inspection and testing procedures to confirm the circuit is safe to be energised.

 

[rickus19]

It is only 1 cable so is that classed as a circuit? it goes to the shed but does not return. It is fused at the main fusebox (30amp). I would say that its larger than 6mm but again am not sure as to which way it is measured. When I look for RCD's all I find are trip switches, so am at a loss as to how I install one of these at every socket. Are you saying that every socket has its own trip switch? Sorry for sounding thick but I don't see how that can be or how to do it.

 

[rickus19]

Do you mean that I should fit something like
http://www.ebay.co.uk/itm/Pre-assem...al_Electrical_Fittings_MJ&hash=item4ac8c216a9

but with 3(number of sockets I will have) 32a trip switches?

 

[ericmark]

Using a Duel Accessory Box like this

one can fit a socket and a RCD fused connection unit (FCU) alongside each other.

from the RCD FCU you can then add as many sockets as you like all being fused to 13A total and RCD protected cost of parts around £25.

Or you can fit a Garage Consumer unit you show link for, either way it allows you to reduce the maximum current using MCB or fuse and add RCD protection.

Cable is rated by cross sectional area of the conductors the Batt cables website does give the outside sizes 6.9 mm x 13.4 mm for a 6mm cable however this will change make to make. That is for twin and earth which does not seem right for a shed. In the main sheds are remote from the house and twin and earth is not a external cable we would normally use SWA (Steel wire armoured) cable.

I find measuring the cross sectional area with calliper hard, and the normal method I used is to try fitting red, blue or yellow crimps onto the cable. If red will go on the 1.5mm or less, if blue will go on 2.5mm or less and yellow 6mm or less so if blue will not fit and yellow fits slack then 4mm and if yellow fits tight then 6mm. Often the size is written some where on the cable.

A circuit means the electric can flow so it has line and neutral when you have two cables going around in a circle and meeting so every socket has two cables feeding it then it is called a ring.

We have debated the fitting of a garage consumer unit and we have not reached a conclusion as to if this need notifying. (See Part P building regulations) However I would with the apparent lack of knowledge on your part advise you get some one who is a scheme member to do the work. Or at least get a quote that way they will likely raise and safety points we may have missed.

 

[ban-all-sheds]

It is only 1 cable so is that classed as a circuit?

Yes.

it goes to the shed but does not return.

//www.diynot.com/wiki/electrics:a2-radial

I think you'd find it useful to work through these:

• http://www.google.co.uk/search?q=electrical+circuits+101
  
  
• http://kevinboone.net/electricity.html
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/domesticinstallations.html
  
  
• //www.diynot.com/wiki/electrics:books
  
  
• //www.diynot.com/wiki/electrics
  
  

I would say that its larger than 6mm but again am not sure as to which way it is measured.

It's the cross-sectional area of the L&N conductors, not any of the overall physical dimensions of the cable: //www.diynot.com/wiki/electrics:flatpvccables.

 

[ban-all-sheds]

We have debated the fitting of a garage consumer unit and we have not reached a conclusion as to if this need notifying.

The people who wrote the law say that it is notifiable.

 

[JohnW2]

We have debated the fitting of a garage consumer unit and we have not reached a conclusion as to if this need notifying.

The people who wrote the law say that it is notifiable.

I agree that there is scope for debate about whether installing such a CU results in the creation of 'new circuits' (which, if it did, would render the work notifiable, even in England). However, if what you say is true in relation to the CU, per se, then those who wrote the law must have a different understanding of the meaning of the word 'replacement' than I do!

Kind Regards, John

 

[riveralt]

We have debated the fitting of a garage consumer unit and we have not reached a conclusion as to if this need notifying.

The people who wrote the law say that it is notifiable.

Replacement of a CU yes.
New Circuit yes.
But adding a CU to the OP's existing circuit in the manner suggested by Eric above is not notifiable.

 

[JohnW2]

We have debated the fitting of a garage consumer unit and we have not reached a conclusion as to if this need notifying.

The people who wrote the law say that it is notifiable.

Replacement of a CU yes.
New Circuit yes.
But adding a CU to the OP's existing circuit in the manner suggested by Eric above is not notifiable.

I totally agree - does that mean that there was a typo in what you wrote above?

Edit: Whoops - I thought I was responding to BAS, not riveralt. The issue is therefore not of BAS having been inconsistent, but of riveralt (and me) saying something different from BAS. My apologies.
Kind Regards, John

 

[ban-all-sheds]

 

[JohnW2]

<a communication from DCLG>

That letter certainly does 'clarify their intentions', and I don't doubt that most of us believe, and would have expected, such to be their intentions.

However, as you're always saying when it comes to the law, unless there are ambiguities that need interpretion - which I don't believe there are), all that matters is what the law actually says, regardless of whether the intent of those who wrote it was something different. No?

However, I'm still confused by your recent post, which seems to be contradictory. Were you expressing the view that installation of the garage CU, per se, was or was not notifiable (in England)? Was it a typo, or what?

Kind Regards, John

 

[riveralt]

It is a sad reflection that having worked with similar civil service clowns in the past double speak or double dutch is a required language.
In clarifying their intentions about the new and replacement cu's and new circuits they promptly muddy the waters by stating..
"Our thinking was that installing a new consumer unit would always be linked with installing new circuits, and therefore it wasn't necessary to refer to new consumer unit in the list of notifiable works"
In the proposal above there is a new cu but not a new circuit so that 'clarification' fails and the work does not need to be notified.