LazerBrain Posted April 18, 2009 Share Posted April 18, 2009 My neighbour has had a couple of fence panels replaced in the last few days and the mains power to my garage appears to have mysteriously failed after 10 trouble free years... The previously buried armoured cable running on my side of the fence is visible on the surface for about a foot by one of the freshly installed fence posts. It seems pretty obvious to both of us that the person who fitted the new fence posts disturbed the cable, although nothing was mentioned to my neighbour. I'm pretty sure there would have been a loud bang when the post digger sliced into the cable! This cable is fused rather than on a RCCD so the risk of electrocution seems pretty high to me. I've seen some armoured cable jointing kits on ebay. I suspect I will need 2 and a length of armoured cable as I think the cable could well be damaged for about 6 inches (based on my understanding of the tool used for making fence post holes.) Replacing the whole run (prob 15m) is out of the question as it would require part of my driveway to be dug up. My neighbour is going to approach the company that did the fencing, but I fully expect them to deny everything. I'm not suggesting that they turned up on horseback and had spurs on their heels... Actually, I probably am, based on previous experience of their work. Anyone used these jointing kits before? Any tips? cheers, Darren. Link to comment Share on other sites More sharing options...
Pendennis Posted April 18, 2009 Share Posted April 18, 2009 Darren, don't consider making a joint of any sort and then laying it back underground, it is not a long term solution. However, if the junction method you intend to use is to remain above ground, it would be acceptable as long as it is weather proof and adequately earthed. SWA glands tends to allow ingress of rain water, so install in a manner that moisture cannot run down the boot cover of the SWA cable. I would use a weatherproof galvanised junction box with both the SWA entering at the bottom so no rain can enter Bolt the two banjo's together to achieve the best earth bonding possible Good luck Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted April 18, 2009 Area Representative Share Posted April 18, 2009 This sort of thing here should do the job. Link to comment Share on other sites More sharing options...
LazerBrain Posted April 18, 2009 Author Share Posted April 18, 2009 Pendennis - Oh - I'd thought that the resin prevented any moisture penetrating the joint. ☹️ This is the kit I was looking at here cheers, Darren. Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted April 18, 2009 Area Representative Share Posted April 18, 2009 Darren, Oh - I'd thought that the resin prevented any moisture penetrating the joint Yes, the resin type of joint prevents ingress of moisture! Make sure that you get the correct size of joint to suit the cable. You'll all so need the correct crimping tool to crimp the conductor joints. I can't remember the details (It's about twenty years since I last used one!) but they come with comprehensive instuctions. Link to comment Share on other sites More sharing options...
DSL Posted April 19, 2009 Share Posted April 19, 2009 I had the same problem with an 11ton excavator sticking its bucket through a buried armoured cable, the electrician used a resin jointing kit that was reburied over 4 years ago & have never given it a second thought as no issues have arisen *thumbup* Link to comment Share on other sites More sharing options...
jackb_ms Posted April 19, 2009 Share Posted April 19, 2009 Darren, don't consider making a joint of any sort and then laying it back underground, it is not a long term solution. I second this point of view, never make a join in the ground. It is a lot better to make the connection above ground in a junction box. Jack PS: Fit an RCD somewhere also Emily, The Very Yellow 21 Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted April 19, 2009 Area Representative Share Posted April 19, 2009 never make a join in the ground Why not 🤔 Supply authorities do it all the time. PS: Fit an RCD somewhere also There is no RCD protecting the cables that the supply authorities bury underground! It is a lot better to make the connection above ground in a junction box. Is that the opinion of an electrician or electrical engineer?? I think not! It is common practice (by professionals!) to joint cables underground with resin cast joints! Link to comment Share on other sites More sharing options...
john milner Posted April 19, 2009 Share Posted April 19, 2009 My dad's job was to do this every day for the electricity board so jointing is safe if done properly. Cables getting dug up that knocked out whole housing estates was a good overtime earner for him. However it needs to be done professionally or there is a real risk of death and/or explosion. Not a diy job and get a RCCD. Link to comment Share on other sites More sharing options...
RussM Posted April 19, 2009 Share Posted April 19, 2009 I agree with totally with Richard, resin joint is the way to go. Our contractors used them many times on cables around a chemical site at up to 11,000v (yes 11kV) to re-route cables including the High Voltage ring; burried and above ground on a pipebridge. No issues as long as it's the correct size and fitted correctly. Russ Link to comment Share on other sites More sharing options...
jackb_ms Posted April 19, 2009 Share Posted April 19, 2009 In my industry making a join in the ground is something to avoid as you never know how good the resin or join will be. There is no RCD protecting the cables that the supply authorities bury underground! This cable is fused rather than on a RCCD so the risk of electrocution seems pretty high to me. I was referring to this sentence. If it was a supply to my garage I would want the supply to be as safe as possible (part P certification spring to mind). Industrial and domestic supply are treated as two different type of supplies by the British Standard so different rules applies. Not a diy job and get a RCCD RCD are now available in a easy wiring package, they are similar to a wall mounted socket. Jack Emily, The Very Yellow 21 Link to comment Share on other sites More sharing options...
Big Brother Posted April 19, 2009 Share Posted April 19, 2009 Underground joints are fine and are very common. If the repair is carried out by a qualified/registered, then I think you will have no other option but to bring the circuit up to current standards and fit an RCD. Steve Link to comment Share on other sites More sharing options...
blade_runner Posted April 19, 2009 Share Posted April 19, 2009 Part p of the buliding regs is mainly for bathrooms and kitchens. if the garage is separate from the house then it will need its own comsumer unit. BS7671 2008 only requires circuits to be protected by an rcd if its buried in the fabric of the building structure less than 50mm if it doesnt have earthed metallic protection and its not suppling any equipment in the bathroom or socket outlets. The buried swa cable need not have an rcd just an over current device, the consumer unit in the garage shoud have an rcd if its got socket outlets, also depending on your earthing system type an earth electrode may be required at the garage end of the swa cable. some area electricity boards dont like the earth being exported from the house to out buildings. An rcd's not required to protect the swa cable from the supply end but if you are going to protect it with one use a 100mA one then have a 30mA one in the consumer unit in the Garage this will give you discrimination and it will trip locally in the garage when you plug your faulty grinder/welder etc in and you wont have to go inside to reset set the 100mA rcd Edited by - blade_runner on 19 Apr 2009 22:25:59 Link to comment Share on other sites More sharing options...
blade_runner Posted April 19, 2009 Share Posted April 19, 2009 PS... Id repair it with a resin kit if possible 'Pinky Pics' here Link to comment Share on other sites More sharing options...
LazerBrain Posted April 20, 2009 Author Share Posted April 20, 2009 Thanks all Having worked with armoured cable whilst wiring a mate's pond pump up a few years back I'm much happier to let a pro fight with the stuff. I've just had a chat with a local electrician who has said that he would replace the damaged section of cable with a new piece of armoured cable and a resin joint at each end. I explained the current setup and his initial thought is that it only requires a RCD at the house end to bring it up to date. He's coming over later in the week to inspect the damage and provide a quote. cheers, Darren. Link to comment Share on other sites More sharing options...
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