Ask a Tradesman
Can i run a cable through the wall and plug it into an existing wall socket to give power to my pond?
I want to fit a weatherproof rcd socket to an outside wall for a fish pond (pump is 12v 10w) running a cable through the wall and plugging in to an existing wall socket. Can I do this?
No as the cable feeding the outdoor socket also needs to be RCD protected, in order to comply with BS7671:2008.
Assuming that you have contacted your local authority building control dept and have part P building regulation consent in place (you need consent to do DIY electrical work in the garden), then the best way to do the job is change the indoor socket to an RCD type and then use a standard non-RCD weatherproof socket outside.
This way both the outdoor socket and the cable through the wall are RCD protected, plus the sensitive RCD socket is indoors and less likely to get affected by the ingress of moisture.
Once you have finished the job, the local authority part P inspector will need to come round and inspect and test your work, so that a building regulation compliance certificate can be issued. (This ctypically costs around £200 - £300 depending on the local authority)
The other option which would be cheaper would be to hire a part P registered electrician to install the socket for you, as registered installers can self certify their own electrical work.
Google part P or visit the electrical safety council website for more information. Please be aware that failure to comply with Part P of the building regulations can result in a £5000 fine.
Hope this helps, please click on "like" if it does.
Answered 10th Nov 2012