Run Electrics out to new external garage

[thedon99]

Hi folks,

I've had a search about but can't see that anyone's asked this already - apologies if they have and I've missed it.

I'm having a new external garage built, and want to run the cable / do the first fix myself. I have a spare way in my consumer unit, so would like to run SWA from the house Consumer Unit under a lawn (probably a spade and a half's depth, perhaps with a edging stone or something over the cable to give it extra protection). My question is how do I bond / terminate the earth of the SWA to both consumer unit's:
- is there a special connector inside the plastic enclosure?
- do both the CPC/Earth and the steel wire shield attach to the neutral bus bar?
- is there a special consumer unit / enclosure to use at the Garage end (I've been looking at the MK Sentry 4 way at Screwfix for about £40 - but can't see anything in the description about SWA termination?)

The garage only needs a few sockets - no heavy loads, and lights (although there will be two external lights - one of which will be a lamp post a few metres away so will have a second SWA run to that).

Hope someone can offer some advice.

Cheers
Don

 

[Chri5]

Most swa cables are glanded to a metal box and the box earthed back.



Don the suggested depth is 600 mm and the job requires cert, which you won't be able to supply. The schemes the sparks register to are explicit, they can only certify work that they ( the sparks) does.

The half way house is to contract a sparks and see if he will allow you to 1st fix with a inspection of the route before back fill.

http://www.tlc-direct.co.uk/Products/TLC20.html

 

[ban-all-sheds]

I have a spare way in my consumer unit, so would like to run SWA from the house Consumer Unit

I would advise you ask your electrician to split the tails and run the SWA from a switchfuse instead.

My question is how do I bond / terminate the earth of the SWA to both consumer unit's:

You don't - your electrician does.

Very few are frustrated navvies - if you want to dig the trench to his requirements I'm sure he'll be only too happy.

Having him supply all the materials will be cheaper anyway.

The garage only needs a few sockets - no heavy loads, and lights (although there will be two external lights - one of which will be a lamp post a few metres away so will have a second SWA run to that).

I would still advise putting in 10mm² SWA as a minimum, in case you ever need the capacity - the marginal cost of larger cable will be insignificant.

Ideally install a couple of conduits with draw ropes - one for any electrical cables, one for phone/data. Unless you enjoy trenching and re-turfing, that is.

 

[thedon99]

Great advice thanks fella's.

To spilt the tails and run from the incoming supply at the Meter cupboard will be a lot more difficult as it'd need to be run under a tarmac drive. The Consumer Unit is going to move to the nearest external wall to the new garage and will allow a much simpler run.

Can you recommend a suitable metal box on the TLC site (or other national chain) for the SWA to terminate to?.

Thanks again.

Don

 

[flameport]

- do both the CPC/Earth and the steel wire shield attach to the neutral bus bar?

No, they do not. Why would they?

The Consumer Unit is going to move to the nearest external wall to the new garage and will allow a much simpler run.

Who is moving this consumer unit?

 

[thedon99]

Hmm good question - that was a dumb thought I hadn't properly thought through!

So I assume the SWA is Glanded to terminate it into a metal box alongside the source and destination of the run, and this box is connected to the MET inside each Consumer Unit?

The builder has a Sparky lined up, but he won't be coming to site for a couple of weeks, so I'm using the advice here to get me up to speed before I meet him. I'm also hoping to change career to be an Electrician, so doing my own install would allow me to get a few jobs signed off towards a NIC EIC domestic installer certificate (I've already done the 17th Edition at night classes but not done any real practical yet)

 

[ban-all-sheds]

The Consumer Unit is going to move to the nearest external wall to the new garage and will allow a much simpler run.

And the reason that when that is done you couldn't also have a couple of henley blocks and a switchfuse put on the wall is.....?

 

[Taylortwocities]

OK
So what is your supply type?
DO you have any services in teh garage, like water/oil/gas?

These are all added considerations.

PS congratulations on getting your "17th Edition" but that only signifies that you can look up something in a book.
But
(and i think you are beginning to realise this)
this is in no way a craft qualification nor does it prepare you in any way for the task(s) you have in mind.

You may have to settle for doing some serious digging and hanging around the builder's electrician to pick up some nuggets of information.

 

[thedon99]

Ban all sheds - sorry, yes I assumed you meant a switch fuse alongside the Meter - Where I'll already have one of those in place to run new long meter tails to the new Consumer Unit position. I can happily have henley blocks and a switchfuse in the new CU location.

Taylortwocities - We've got TN-CS and no other services in the new external garage.

I was hoping to do an EAL DI course to get some practical, but it seems the centres aren't running them at the moment due to the regs changes. I did the DISQ at NIC EIC but that was 90% thoery and overlapped heavily with 17th.

 

[ban-all-sheds]

The EAL DI course has no practical, unless you need to learn which way hold a screwdriver and how to connect sockets and switches....

 

[Taylortwocities]

Thedon:

worth a read
http://electrical.theiet.org/wiring-matters/16/elect-inst-outdoors.cfm?type=pdf

Its written in 16 edition times but still mostly relavent.