Greetings Posted July 27, 2015 Report Share Posted July 27, 2015 I'm puzzled by this one. The sockets are connected in series which is the first thing that doesn't seem right. Furthermore, I have isolated a connection between two sockets where ground is shorting with neutral. I can see that whoever attended to these sockets in the past has left the ground disconnected in one of the first sockets of the series. Is this something I should be concerned about? The "problem" must have been present for years but I've only now discovered it because I'm changing the number and position of contacts. What do I do? If this is safe I'd rather leave it the way it is considering it's been working like this for years. I can also isolate the earth from both sides, not just one. Alternatively, I can fix this which will mean digging into the wall. Quote Link to comment Share on other sites More sharing options...
ooo Posted July 27, 2015 Report Share Posted July 27, 2015 Will you be plugging anything with metal casing into it at any point ? Quote Link to comment Share on other sites More sharing options...
tomturd Posted July 27, 2015 Report Share Posted July 27, 2015 Sockets can be connected in series, its called a radial circuit and that's totally ok according to my electrician. You need a fatter cable because the electricity is delivered to the socket from one direction only. But the 'last' socket in your chain might go back to the CU, which will make it into a loop. You can use thinner cables because the electricity is delivered to the socket from both sides. If you break the loop (by drilling through a cable or something) then you effectively have 2 radials where a loop once was, the sockets still work but now each radial is on underrated cable. That, and that having an earth is generally a good thing, is the about the extent of my electrical knowledge Personally I would get digging in the wall. Quote Link to comment Share on other sites More sharing options...
GavLawson Posted July 27, 2015 Report Share Posted July 27, 2015 I doubt the circuit is wired in series. Its probably a radial. The first thing to do is unplug everything and Isolate the circuit. Make sure all earths are connected. Then test at the board between l-e l-n n-e using a megger or ohmmeter. Half the circuit and repeat until you have narrowed down which cable is causing the problem. Quote Link to comment Share on other sites More sharing options...
Greetings Posted July 27, 2015 Author Report Share Posted July 27, 2015 Will probably have to call an electrician. That last post has me completely lost How can I find out if it's radial? I know that the lights will dim slightly if I plug something major in like a heater so this to me suggests a drop in voltage which shouldn't happen with a radial? I don't think I'll be plugging anything with a metal casing to the wall, could you give me an example of such a plug/device? The wires are copper 1.5mm or ~9/16ths using the imperial system so pretty thick, or so I think.... Quote Link to comment Share on other sites More sharing options...
tomturd Posted July 27, 2015 Report Share Posted July 27, 2015 1.5mm diameter or 1.5mm area? In the UK I think the standard is 2.5mm for loops and 4mm for radials. Ring/loop looks like this: Radial looks like this You can find out if its a radial by disconnecting one of the wires in one of the sockets (breaking the chain). If the other sockets further down the chain stop working then it's a radial, if they keep working its a ring (as power is supplied from both sides) 1 Quote Link to comment Share on other sites More sharing options...
manuel Posted July 27, 2015 Report Share Posted July 27, 2015 If the current wiring is as bad as said, then that may not be the best test, and even thickness of wire may not be correct. Get an electrician in to check the lot. Quote Link to comment Share on other sites More sharing options...
waybe2014 Posted July 27, 2015 Report Share Posted July 27, 2015 I studied to be an electrician and to be honest what I've seen scared me so much I decided to not be one. Multiple near misses from dangerous wiring. Quote Link to comment Share on other sites More sharing options...
tomturd Posted July 27, 2015 Report Share Posted July 27, 2015 If the current wiring is as bad as said, then that may not be the best test, and even thickness of wire may not be correct. Get an electrician in to check the lot. I should have added quite a big disclaimer.. I only know enough to be dangerous In this case if it was me I think I'd probably rip it out (safely), do the chasing and run new cables myself then get an electrician in to wire up of sockets, do the CU stuff (that's one place I definitely don't mess around with) and sign it off. Quote Link to comment Share on other sites More sharing options...
GavLawson Posted July 27, 2015 Report Share Posted July 27, 2015 (edited) Don't go ripping out anything until you've had a sparky look at it. I'm a spark to trade and would say a lot of faults I have encountered look worse than they actually are. I just gave you a quick description on how to track the fault down I can give you a better one later when i've got time, but if you don't feel confident you should probably get someone out. I just re-read your post how do you know theres a short between earth and neutral? did you physically disconnect both the earth and neutral from the board before testing? on most UK/EU systems the N+E are actually combined at the incoming fuse. Edited July 27, 2015 by GavLawson 1 Quote Link to comment Share on other sites More sharing options...
Greetings Posted July 27, 2015 Author Report Share Posted July 27, 2015 Judging by those pics I'm pretty sure it's a radial. Current goes from one socket to the next but there is definitely a last socket which only has wires going into it and none coming out. There are also no sockets with 3 sets of wires. An electrician is coming over tomorrow to take a look. Tom, it's 1.5mm in diameter. 2.5 and especially 4mm sound awfully thick, I have a few UK plugs in my room and they don't look like they could accommodate such a massive wire. I could well be wrong though. Gav, I'm guessing there's a short because there's continuity between neutral and earth. I've isolated the two sockets (or one cable) which are responsible for this. I'm also pretty sure that after opening one of these two sockets I found the earth disconnected which suggests that someone before me was aware of this problem. The reason I'm somewhat worried is that the problem concerns one of the first sockets in the circuit. So if it's radial there will be no earth in my entire room, correct? Quote Link to comment Share on other sites More sharing options...
tomturd Posted July 27, 2015 Report Share Posted July 27, 2015 An electrician is coming over tomorrow to take a look. Tom, it's 1.5mm in diameter. 2.5 and especially 4mm sound awfully thick, I have a few UK plugs in my room and they don't look like they could accommodate such a massive wire. I could well be wrong though. The reason I'm somewhat worried is that the problem concerns one of the first sockets in the circuit. So if it's radial there will be no earth in my entire room, correct? 2.5 and 4mm don't relate the diameter of the cable, I think it represents the cross section/area. Each strand of copper in a 2.5mm cable is about 1mm diameter if I remember correctly. Good that you have a pro coming round. It does sound like you have no earth in any of the sockets. I wouldn't be too concerned. My whole lighting circuit didn't have an earth and we have lots of metal wall lights, but in the 40 or 50 years it was like that, to my knowledge, nobody died. Still worth getting it sorted though I think, especially if you're planning on moving sockets anyway. 1 Quote Link to comment Share on other sites More sharing options...
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