Electrical supply to Garage - Advice

[mjdresser]

Hi,

Firstly I will not be doing this myself, I will be contacting an approved electrical installer to get a quote for this work. I am just looking for some basic knowledge so that I know they are using the right components for the job.

1. My garage is about 3' away from the house and will require that the electrical supply be brought into the garage by a cantenary wire. What kind of cable should they be using, SWA or will be the standard grey stuff often behind walls?

2. What will they use to support the wire rope from the garage as this will be raised, I have see all sorts used on other people houses from, angle iron, round tubing to TV aeriel support poles.

3. I would like 2 flourescent lights in the garage and 1 double socket. With the possility to add some outdoor sockets for say the lawnmower and possibly a pond pump at some point in the future. What kind and size consumer unit should they be using allowing for some expansion, I don't want the minimum installing and then finding I have to have it replaced at a later date due to the load.

I appreciate all your help and advice if you have any, what too look out for when they are doing the job.

Many Thanks in advance.

TLE

 

[oharaf]

There are a whole host of ways of supplying overhead power, and this will vary according to cable type.

'The Grey Stuff' would need to be contained within conduit/ ducting, a catenary wire can be used as a support but will have to support the cable in accordance with tables 4A and 4E.

I would want the power supplied by at least a 10mm cable from the cu to a GARAGE specific cu with a 30mA RCD

 

[kwikfix328]

10mm² for 2 x 50 watt flo tubes and a socket for a lawnmower/garden/diy tool and possibly a pond pump, seems a bit excessive, especially given the distance.

It will certainly be future proof.

'Approx' how long would the cabl;e need to be between your existing consumer unit, which should be the garage supply's source and the location for your new Garage CU.

 

[mjdresser]

Thanks for the reply's so far..

I am guessing that the approx length would be around 10 meters to go from the house cb up into the floor space, and out through the side of the house out too the garage.

TLE

 

[ban-all-sheds]

Isn't it strange how some people have so little trust in "approved electrical installers" that they feel the need to "look for basic knowledge" to be able to check that someone who has qualifications and knowledge which are far beyond basic level is using the right components.

And isn't it strange how these people think that whatever they get told here by anonymous posters must be correct, whereas what they are told by "approved electrical installers" needs to be checked.

And isn't it strange how these people think that asking a couple of basic questions is going to give them all the knowledge they need to check that "approved electrical installers" are using the right components and to oversee them while they are doing the job to check that they are doing it properly.

 

[baz1968]

I can't see what's strange about wanting to be involved in this project and having an understanding of the nature of installation rather than just paying someone else to carry it out. Anyone who reads the sound information given on this forum would soon realise that info from you (BAS) and other expert forum users is good, free and impartial and not the opinion of a contractor with only a monetary motive. If i am paying for a service i like to know as much about it as possible, and were better to gain such advice than from no biased experts with nothing to gain Just my opinion...

 

[mjdresser]

Thanks to all those contributed. It has given me a small amount of understanding or what's required.

ban-all-sheds I trust whole heartily tradesmen, I simply want to educate myself a little. There is nothing wrong with that as far as I am aware, in fact it’s something I strive to do. I myself was a tradesman (cabinet maker\antique furniture restorer now a software developer) and I wouldn't have a problem in anyway with someone going out and getting an understanding of a job before they commission me to do the work, as long as they realise I am the professional with the qualifications and experience.

 

[mjdresser]

Sorted, I have an electrician who is going to do the job for me. He has asked that I install the support pole for the wire rope to suspend the cable on. I'm happy to do this as it saves a little on the job.

He suggested using a TV aerial mount and pole, would this be ok or is there a better method that someone can suggest. I have checked round and cannot find anything else similar, or that is designated for that type of job.

Thanks

TLE

 

[oharaf]

TLE

I don't really see why the need for a 'support pole'?

Surely a catenary wire is all that is needed?

Does the cable need to be suspended higher that one of the buildings actually is?

Can you take a pic of where this all is happening, I just like to have a view of the situation, I'm sure your spark knows what he is doing

 

[mjdresser]

The garage height is only about 8 - 9' high, and he said the wire would need to run at least 12' above, So attaching the wire rope to the house is fine, but I think a pole is required to be attached to the garage in order that the wire rope can be attached to that. I can't take a pic at the moment, but can do later.

Thanks

TLE

 

[oharaf]

With you, get a pic when you're done

 

[mjdresser]

Sorry, didn't manage to get a picture as it was rather late when I got back from work last night.

I have spoken to the electrician and he was saying it needs to be raised up as the cable needs to be suspended at least 12' up. The garage is only 9' high and 4' away from the house.

TLE.

 

[ban-all-sheds]

I have spoken to the electrician and he was saying it needs to be raised up as the cable needs to be suspended at least 12' up.

Yup.

Well - 3.5m if you want to be precise - maybe he's specifying an extra 6" at the ends of the cable to allow for the sag...

 

[roberta1000]

Isn't it strange how some people have so little trust in "approved electrical installers" that they feel the need to "look for basic knowledge" to be able to check that someone who has qualifications and knowledge which are far beyond basic level is using the right components.

BAS, I couldn't decide if this was tongue-in-cheek or an outrageous display of superconfidence in your fellow-man.

I can certainly tell you that in the last twelvemonth I could have been well roasted by various tradesmen for PVC soffits, garage roof refelting and gas boiler servicing (dangerous - needs a replacement mate) if I hadn't taken the trouble to find out a bit about things. And speaking as a bit of an old-timer there do seem to be more chancers around now with no decent apprenticeship under their belts. Of course noone has ever heard of a dodgy sparky out to shaft you though...