My Mother's having a sewage treatment plant installed. They laid the power cable today for the aerator but I'm not happy with it. Where the cable crosses the garden its buried in 2.5 inch flexible conduit pipe. At the house it exits the conduit just above ground level (no hockey sticks used) and runs up the wall with cable clips and through the wall into the consumer unit on the other side. Except they've drilled it through the window sill and downhill too so that water will track into the house and the sill will rot. They've run the cable but not connected it yet. The cable used is ordinary three core round flex. Not armoured. My question is should this cable be armoured? What happens it the conduit gets flooded or rodents get in? And is it acceptable practise to clip an unprotected non-armoured power cable to an outside wall and pass it through a window frame or through masonry? I shall be querying it in the morning and I need to get my facts straight. Advice appreciated.
Not an electrician but my garage power had to be armoured cable with tape over the top to indicate it was there. Also it was drilled upwards through the wall to stop moisture entering as you suggest.
Im guessing you need to quote building regs dont know if this is the right one but something like it.... http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_P_2013.pdf
In a word, no... It's not acceptable. It should be in armoured conduit, and should have protection and warning tape above it. I'm pretty sure you can find the latest IEE Regulations on-line, but if you have any doubts contact a qualified electrician or even local Trading Standards. Your local Citizens' Advice Bureau should also be able to point you in the right direction. It's never worth taking any risks with electricity and it sounds to me like this was fitted by a bunch of cowboys...
Gimlet Tricky to make a judgement without seeing it, but the cable that runs across the garden should be of sufficient size to carry the intended load, and of such a size that the voltage drop when loaded is less than 4% of the supply voltage. It should be protected and buried at a depth of no less than 500mm and warning tape laid above the cable. As the cable is running outside it should also be protected by an R.C.D, or R.C.B.O who's rating is no more than 30mA. The cable running up the wall should be protected and where it goes into the house should be drilled in such a way as to prevent moisture penetrating the building. I would run the cable from the outside of the house in s.w.a cable, the choice of the cable size being determined by the length of the run and the intended load. Hope that helps. I stand corrected re: the specific figure of 500mm I mentioned, although that is good practice generally, take a look at this: http://www.tlc-direct.co.uk/Book/7.13.3.htm http://www.tlc-direct.co.uk/Book/7.13.3.htm
Mate you need to find a document named Njug, it has a pretty picture showing the depths of utilities ie water, gas, electric cable blah blah.
It is common not use hockey sticks as the flexible conduit allows the cable to be routed wthout stress. The cable must be mechanically protected ( in reallife this means swa). It must be external rated, e.g. HORN7F...most cables degrade with exposure to the rain and sun. Good practice would be a downward hole from inside to out with the hole dressed to prevent moisture and creature ingress. Correct cable cleats on appropriate spacing. As @CRYSTALJOHN says, at least 500mm down with tape / sand and gravel markers. Almost definitely separate earth arrangements at the plant. An infraction isn't committed until the supply is switched on...ask for the electrical safety certificate before paying any money. The person under taking the work must be competent and able to prove it, by having an 17th edition qualification. Pm me if you want to see one.
Sadly I don't think the correct water proof way of drilling a cable access is defined in an electrical standard...its in building practice somewhere.
Interesting Vince -'National Joint utilities group' where do I join The issue of concern here is of course, recommended good practice and conforming with BS7671: A depth of burial of less than 500mm is usually inadvisable as shallow laid cables may be inadvertently damaged by general gardening etc, cables that cannot be buried at a reasonable depth should be specifically protected, e.g. by ducts encased in concrete, or installed along an alternative route. See HSG47 "Avoiding danger from underground services".
LOL Hi John, Its an official document and is well known in the gas industry we ask our contractors to abide by it as there is more publications with regards to digging near trees so on and so forth. IGEM also quote the same depths in their documentation (Institution of Gas Engineers & Managers) They regulate the gas industry.
When I relayed my mains cable (incoming) I dug it 650mm...around 1\3 of my homes perimeter. Very scary since i don't have foundations! When I intercepted the current one it was 80mm under the top soil!! It was laid by the electric board!!
I think the confusion here is we deal with main fuse \ distribution board onwards. This document refers to the macro structure in the streets.Which should be greater or better, but isn't.
Well on building sites we also stipulate they use the same depths in this document. GAs services in private ground i.e peoples front gardens have to be minimum 450mm deep
As has already been pointed out this installation is not acceptable as JR45, Crystaljohn and others say, but I would add that he is also acting illegally by not following the regs, and even if he was following the regs he requires certification to perform the work. If he has the required certification he should know better, if he doesn't have the certification he is again acting illegally. Either way he doesn't have a leg to stand on.
We are saying the same thing. Up to the header fuse is the responsibility of the electric board, from there it is the installing\ certifying electrician's responsibility. Different standards apply.
The "crime" occurs at the point of applying power without certification or certifying a substandard installation.
Every week I come across active works that would not meet regulations. Cheap builders, dodgy developers and polish electricians! This week ...working in a barn on a dairy farm...developer using household twin n earth... IEE strictly states mechanically protected cable.
