Garage Wiring - Socket Lighting Advice

[lozinger99]

Hi All,

I have an armoured cable running down to the garage whcih did supply electricity to a socket/lights until a few years back when it was disconnected at the main box in the house due to the water coming in through garage roof.

The garage roof is now repaired and Id like to turn into a bit of workspace, would liek to put some new lights in and three double sockets.

My plan is to do the research, do the work myself (ie the cables, boxes etc) and then get a qualified sparky in to give it the once over and hopefully all beign well connect it up and sign it off.

My first question though, is about the limits I can have coming off that armoured cable. Is three sockets and lights ok?

Any help much appreciated.

 

[DaftPunk]

What size is the cable and how long is the run from the mains to the garage?

 

[AndyPRK]

A picture of what you have in the garage where the cable comes in would be good.

Are there any fuses ? or straight to the first socket ?

 

[lozinger99]

Hey Daftpunk/Andy - thanks for your reply - makes sense that this info would help!... I will come back with more info on the distance and the full skinny on the cable/pics etc.

 

[ban-all-sheds]

My plan is to do the research, do the work myself (ie the cables, boxes etc) and then get a qualified sparky in to give it the once over and hopefully all beign well connect it up and sign it off.

"Signing off" doesn't work like that.

My first question though, is about the limits I can have coming off that armoured cable. Is three sockets and lights ok?

• //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/20070327014113/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html <- Specify 2-core cable and PVC, even if that is not what you are using or it will make invalid assumptions.
  

 

[lozinger99]

Cheers - I have uploaded a pic of the cable and box that comes into the garage.

//www.diynot.com/network/lozinger99/albums/21328

The cable runs down the garden, through the house - distance approx 40ft.

Hope this helps, many thanks in advance.

 

[lozinger99]

...and the garage space is about 5m by 4m (if that is relevant)

 

[ericmark]

Untitled

• lozinger99
• 14 Jul 2014
• 1

Your pictures show current limited to 13A and since two bit of cable feed the FCU one would assume off the house ring circuit.

Untitled

• lozinger99
• 14 Jul 2014
• 1

As to the RCD protected socket to best of my knowledge only the socket will be RCD protected not the shed supply. So it would seem a 13A supply total to the garage.

You can for convenience have as many sockets as you like in the garage but total can never exceed 13A. Using a switched FCU like you show in picture with a 3A fuse as the light switch will makes lights easy but I would consider swapping the switched FCU in house for one with RCD protection built in so whole garage is RCD protected and use old one as light switch in garage.

As to existing RCD socket does not matter having one feed another but if you have a use for it else where once the RCD FCU is fitted it could be replaced for standard socket.

 

[lozinger99]

Thanks for this - the armoured cable does go directly to the consumer unit is this makes a difference?

 

[ericmark]

It does seem a little over kill to use a consumer unit in a garage feed from a 13A fuse but if already there then no problem.

 

[DetlefSchmitz]

Eric, I could be wrong but I think you are looking at it back to front.

 

[lozinger99]

OH no sorry, I mean the cable goes directly from the consumer unit in the house straight down to the garage and is not off on a spur, if that is a little clearer.

 

[AndyPRK]

If you are only using one power tool at a time, one option would be :

Remove the front of that socket and using the back of it as a junction box.

Fit an RCD FCU next to it (if there is no RCD in the house CU). (otherwise a normal FCU like the one above it)

e.g.
http://www.ebay.co.uk/itm/RCD-Metal...?pt=UK_Sound_Vision_Other&hash=item2a1b15eda4

Connect sockets up to the FCU. They will be limited to 13A but it shouldn't be a problem.

Fit metal blanking plate.
http://www.ebay.co.uk/itm/BG-Metal-...al_Electrical_Fittings_MJ&hash=item3f3961ab37

 

[Les9000]

I agree with DetlefSchmitz that Eric was looking at it back to front.
As I understand it:
- the SWA cable (size unknown) is fed from "the main box in the house" although disconnected due to water leak.
- there is no C.U in the garage. SWA is possibly fed from its own fuse/MCB (rating unknown) in house C.U.
- In garage, the SWA feeds that metalclad RCD socket, the FCU above it is the light switch, and the 2 cables above it feed lights.
So the 13A limit for the garage referred to by 2 people does not exist.
Obviously depending on size of fuse/MCB and of SWA, actual max current allowed may be a little more.

 

[ban-all-sheds]

So the 13A limit for the garage referred to by 2 people does not exist.

No, but if the SWA is not on an RCD circuit and you don't want a 13A limit then you'll have to add RCD sockets for the new ones, and decent metal ones are not cheap.