Please can someone provide some definite guidance or recommendation as to what type of extension lead I may use for providing a temporary socket to a summer house ( Maximum current requirement is less than 13Amps) is allowed without the need for obtaining Part P.
I am considering using a ready made up extension lead that can be purchased fron a well known DIY store. The lead consists of 25mtrs SWA cable, glands, single 13 amp socket and flex for connecting into an existing socket outlet via a RCD 13Amp device. For the pupose of the question assume that the Voltage drop and earth loop impedance characteristics meet with the BS requlations.
This extension can be connected and run from the garage socket outlet via the 13amp flex converted to the swa cable and routed either:
1. visibly along the boundary fence and overhead into the summer house and screw the supplied socket onto the interior wall, thus providing non permanant power supply for genreral usage.
2. Bury the armoured cable as per recommended method i.e 600mm deep, covered in sand and marked by using approved electrical warning tape. The cable will be connected at the a end garage via flex as above and be routed into the summer house and screwed onto the interior wall. possibly semi-permanant!
There is a link to the free Part P download in projects section. If you attach any cable to the wall etc. Or as you propose bury it in any of the special locations then as far as I can see it comes under Part P even if only plugged in. Although there is an exception for pre-fab kitchen units etc.
Because of the number of accidents caused by the use of extension leads New Zealand repealed their Part P. But we no longer have a woman in charge so can't see that happening.
There are many ways people try to get around the law. As to if it would stand up in court is another matter. And the distance you are considering may be too great for TN-C-S earthing to be effective which means some very careful planning would be required not something which could be answered remote from the job.
The Part P document is very open to interpretation. There is a link in Projects area and you can read yourself. There are all sorts of loop holes but as it if they would stand up in court is another matter. I would think it would need someone to complain to start with.
Personally I could not care less about Part P but I do care about general safety and when a house is supplied with a TN-C-S supply also called PME there is a limit to over what area the earth is effective. If you could say 30 foot that would be easy but that's not the case and when supplying sheds, garages and the like careful consideration is required as to if one should use the TN-C-S or a TT supply.
The use of RCD's has reduced the risk but not removed it and to assess the risk you need some expensive test gear.
As with most things one can normally just look at it and have a good idea what will be required but I can't really help with this mode and as a result I don't feel I should be giving anything but vague ideas as it would be so easy to get things wrong.
If I was to do the job I can borrow my son or father-in-law's meters and take readings. As far a cable route I would select a safe route and Part P would not be used to dictate where or how is was going to be laid.
Please remember what I say hear will be read by many and people jump to wrong conclusions so easy so I have to be careful not to say something that can be miss read. Which is why I always direct people to read it for themselves it is in plain language if anything too plain and as a result can be miss read.
Thanks for your initial and subsequent comprehensive and useful reply. I fully understand you explanation and have downloaded Part P and read the relevant section relating to extention leads/cable for providing minimum safe temporary suppy to un-notifiable work.
My understanding is that there is a major contradiction in the Part P on this matter, namely, on the one hand it expessly forbids providing cables across gardens unless the Job is notifiable or a Part P registered qualified person undertakes the work. Later it explains that providing an EC approved unit i.e. the DIY supplier selling the armoured cable and equipment then the DIYer is entitled to carry use this method of providing a 13amp supply without the need to give notification to the local authority.
I clearly take your point about the importance of having the correct earth supply meeting the BS standards and in my case would purchase the extension armoured cable solution with 4mm2 three core and a good quality RCD device fitted in the serving/originating 13 Amp plug/socket.
This in my view is not that different from the 20Amp cable arrangement which I use for my caravan when Touring and the primary supply is already provided on site with appropriate circuit protection.
One again, I am sorry if if have taken up too much of you time and in summary it seems that I should be able to use the DIYer's solution providing all earthing and correct circuit protection is used, since this comes under non-notifiable work.
Very best regards Eric, I really do appreciate the help and direction you have set for this old spark.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!