Power To garage

[eddiewakey]

Hi All,
I realise this question has probably been asked a thousand times however.
I want to run some power to my garage, i realise that it will need to be armoured cable, burried at a quite a depth.

I will have a small CU in the garage, covering what will be a couple of sockets (trickle motorbike charger, occasional vaccum), a strip light, and an LED security light - so not much power draw.

I have 2 questions,
What size breakers would i need in the CU?

Also, by far the easiest option in terms of not causing issues to the decoration of the house, would be to wire this in in the outside box, after the electric meter, i believe there is an isolation switch/fuse in there, so that shouldn't be an issue. - is this acceptable?


THanks

 

[PrenticeBoyofDerry]

What size breakers would i need in the CU?

For mini CU:
1 light circuit 6A MCB
Power for sockets 32A or 20A MCB, depending on load required. The option is yours 20A would require 2.5mm T&E cable, 32A radial 4.00mm or ring 2.5mm T&E
Socket will require RCD protection you can get mini/garage CUs with this protection available at the isolator switch.

Also, by far the easiest option in terms of not causing issues to the decoration of the house, would be to wire this in in the outside box, after the electric meter, i believe there is an isolation switch/fuse in there, so that shouldn't be an issue. - is this acceptable?

It would be wise to fit the distribution cable to a MCB in Consumer unit, if you installed directly after the meter, there would need to be a means of isolation and cable would need to be fused and rated correctly.

 

[ban-all-sheds]

What size breakers would i need in the CU?

• //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
  

Don't forget that you'll need to do testing of those new circuits, before and after energising.

Also, by far the easiest option in terms of not causing issues to the decoration of the house, would be to wire this in in the outside box, after the electric meter, i believe there is an isolation switch/fuse in there, so that shouldn't be an issue. - is this acceptable?

As long as the cable is adequately sized. It should also have its own isolator.

If you're using the TLC calculator, tell it 2-core SWA or it will do 3-phase calculations, and PVC or it will assume it can run at 90°

• http://www.tlc-direct.co.uk/Book/7.13.3.htm
  
  
• //www.diynot.com/wiki/electrics:swa-gland
  
  
• http://electrical.theiet.org/wiring-matters/16/elect-inst-outdoors.cfm?type=pdf
  

The work is notifiable, BTW - you'll need to apply for Building Regulations approval before you start.

 

[eddiewakey]

Thanks for the advice guys,
When you say it will need an isolator, is that in the outside box next to the meter?
So we would have

Main Fuse -> Meter -> House Wiring
-> Isolator -> Garage Wiring


Or could i just put an isolator in the garage?


Is there a cost for notifying?
If so would a cheaper option be to lay the cables, run the trench etc myself, put all equipment in place, and then get someone who can self cert, to connect it all up?


Thanks

 

[ban-all-sheds]

Thanks for the advice guys,
When you say it will need an isolator, is that in the outside box next to the meter?

Possibly.

In theory you aren't supposed to have your own equipment in there - in practice as long as it's not in the way of the supplier's bits'n'pieces nobody will care.

So we would have

Main Fuse -> Meter -> House Wiring

-> Isolator -> Garage Wiring

Yup - keep it off the house CU completely. Actually, what you need is a switchfuse, not just an isolator, as the cable needs overcurrent protection. The MEM 800KMF is nice and compact.

Or could i just put an isolator in the garage?

No, you need something at the origin.

Is there a cost for notifying?

Oh yes.

If so would a cheaper option be to lay the cables, run the trench etc myself, put all equipment in place, and then get someone who can self cert, to connect it all up?

Probably, but you must find that person BEFORE you do any work, and let them tell you what to do. There aren't many electricians who wish they had more opportunities to dig trenches.

 

[securespark]

There aren't many electricians who wish they had more opportunities to dig trenches.

I didn't mind as long as I got paid!!

 

[ban-all-sheds]

Just the weather for it too.

 

[eddiewakey]

Thanks for your help guys! Very helpful!
Whats the likely cost of notifying the LA?

 

[ban-all-sheds]

The one you'll find on their website.

 

[eddiewakey]

The one you'll find on their website.

Cant find it anywhere on Leeds city council website

 

[riveralt]

The one you'll find on their website.

Cant find it anywhere on Leeds city council website

£235 for Building Notice application - for electrical notifications - before you start.
Plus their Building Notice application form has this little kicker..........

An additional charge of £235 is payable where Electrical work is not to be certified as compliant with the Building Regulations by a person or body competent and registered to do so.

http://www.leeds.gov.uk/docs/building_notice_revisedupload form_oct2012-ver2.pdf

 

[EFLImpudence]

Strange the two figures are identical - obviously carefully worked out to cover time and labour.

If the additional charge is for inspection, testing and certification then what does the initial charge cover?

 

[EFLImpudence]

[even more cynicism] Oh, just realised - if you don't need to pay the additional charge then you don't need to pay the initial charge either.

So - it's £470 - bargain. [/even more cynicism]

 

[JohnW2]

If the additional charge is for inspection, testing and certification then what does the initial charge cover?

Quite. What exactly can they mean by "...certified as compliant with the Building Regulations by a person or body competent and registered to do so" other than someone who would be able to self-certify in the first place? Is there perhaps some form of 'registration of competence to certify' other than membership of a self-cert scheme?

Kind Regards, John