Have just extended an existing ring main in my kitchen to add some new sockets. Have checked an double checked all cabling at sockets, and have checked continuity of the ring between all sockets and also end to en at the CU, but when I power up there is no power to any sockets. Have tried another MCB - same story. have even tried wiring only one socket directly (radially) back to the CU at both ends of the ring but no joy - bit of a mystery to me - can anyone suggest a solution?
No power to ring main sockets
- Thread starter reubendiaz
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Have you tried resetting your main switch, the RCD may have tripped when you were altering the wiring due neutral/earth short.
Some RCD's need to be turned off then on if they trip and are not always fully down if they trip- this is presuming you have an RCD.
Other than that have you anything to check that there is definately power leaving the MCB, multimeter, test lamps etc?
Some RCD's need to be turned off then on if they trip and are not always fully down if they trip- this is presuming you have an RCD.
Other than that have you anything to check that there is definately power leaving the MCB, multimeter, test lamps etc?
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You say you have done the temporary cross of cables and proved it to be a ring main. Therefore the cables must be sound. You don't give readings but I would assume less than 1.44 ohms. Assuming there are other items working from same consumer unit then only two possibilities.
1) You have a short circuit maybe temp shorting wires left in place from measuring the loop impedance?
2) The MCB/Fuse is no good.
There is a third and that is you have not done as you say and tested the ring main. However if you are not doing what you are reporting then there is no way anyone could work out what you have done.
I know there is no Part P in Scotland but I think there is a similar regulation which you will have to comply with?
1) You have a short circuit maybe temp shorting wires left in place from measuring the loop impedance?
2) The MCB/Fuse is no good.
There is a third and that is you have not done as you say and tested the ring main. However if you are not doing what you are reporting then there is no way anyone could work out what you have done.
I know there is no Part P in Scotland but I think there is a similar regulation which you will have to comply with?
bigjon - no rcd on this circuit, so it's not that.
ericmark - there is no short as you suggest, and I have tested out the ring as I say - also tried another mcb.
Time to get a pro in I think - as you point out, I need certification any way, but I'd also like to know why it's not working.
ericmark - there is no short as you suggest, and I have tested out the ring as I say - also tried another mcb.
Time to get a pro in I think - as you point out, I need certification any way, but I'd also like to know why it's not working.
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Although rummer has it that amendment 1 will change the RCD requirement for existing circuits as it stands BS7671:2008 also know as 17th Edition required all new sockets under 20 A need RCD protection with the exception of a shaver socket of course. Also any cables buried in the wall at less than 50 mm deep unless one of the specials like Ali-tube have been used also need RCD protection.
From what you have said the sockets you have fitted will not comply. Under Part P, and yes I know it is not Part P in Scotland but it is similar, electricians can pay to become members of a scheme and self certify. However all these schemes require the electrician to follow BS7671:2008. Although the local authority building control (LABC) can pass other systems and they don't have to follow BS7671:2008 it becomes a problem for electricians as they have to follow what the governing bodies tell them.
As a result if you get an electrician to correct it for you likely he will want it to be to British Standard and will want to fit a RCD of some type.
I do remember as an apprentice carefully following the procedure for testing a ring main which as you will know if you have done it involves disconnecting the wires at the consumer unit and connecting them together with block connectors then plugging the 200ma low ohm meter into each socket to check all have same readings and there is no figures of 8 connections. Having done this it was home time and next day I forgot to return and remove the links and reconnect. So this was what I thought you may have done.
However many DIY people don't have a clue how to inspect and test and it may be your method of testing a ring main does not follow the method recommended in the Guide books published by the IET (Was IEE).
Although it will not test for figure of 8 connections removing any socket with power turned off which is on the ring main one should be able to measure continuity between each pair of wires. This is often considered by DIY people as testing it is a ring main. It is of course better than nothing but if there is a figure of 8 connection it can give misleading reading. From what you have said I wonder if this has happened in your case?
From what you have said the sockets you have fitted will not comply. Under Part P, and yes I know it is not Part P in Scotland but it is similar, electricians can pay to become members of a scheme and self certify. However all these schemes require the electrician to follow BS7671:2008. Although the local authority building control (LABC) can pass other systems and they don't have to follow BS7671:2008 it becomes a problem for electricians as they have to follow what the governing bodies tell them.
As a result if you get an electrician to correct it for you likely he will want it to be to British Standard and will want to fit a RCD of some type.
I do remember as an apprentice carefully following the procedure for testing a ring main which as you will know if you have done it involves disconnecting the wires at the consumer unit and connecting them together with block connectors then plugging the 200ma low ohm meter into each socket to check all have same readings and there is no figures of 8 connections. Having done this it was home time and next day I forgot to return and remove the links and reconnect. So this was what I thought you may have done.
However many DIY people don't have a clue how to inspect and test and it may be your method of testing a ring main does not follow the method recommended in the Guide books published by the IET (Was IEE).
Although it will not test for figure of 8 connections removing any socket with power turned off which is on the ring main one should be able to measure continuity between each pair of wires. This is often considered by DIY people as testing it is a ring main. It is of course better than nothing but if there is a figure of 8 connection it can give misleading reading. From what you have said I wonder if this has happened in your case?
Schoolboy error - my CU is split and I had foolishly connected neutral to the RCD side. Thanks for the advise about the need for RCD - not sure whether that applies to new sockets in an existing circuit, but in any case I will connect this ring to a spare way on my RCD. BTW before anyone reminds me I do plan to have this work certified by a pro.
Thanks to all who took the time to reply.
Thanks to all who took the time to reply.
When you wrote your original question; did you have power anywhere?
edited out a 'no'
edited out a 'no'
No power anywhere on the ring in question; why do you ask?
What I meant was, were any other circuits dead as well as the ring?
Because, if I read the post correctly, if you had the ring neutral wires on the RCD neutral bar then the RCD should have tripped off (or not turned on).
Was it that you had the RCD switched off while you were trying the ring?
Because, if I read the post correctly, if you had the ring neutral wires on the RCD neutral bar then the RCD should have tripped off (or not turned on).
Was it that you had the RCD switched off while you were trying the ring?
Very good point. Not quite sure if I understand what happened there. Because I couldn't work the power problem out, I called a pro, and of course he figured out pretty much right away what the problem was. When he looked at the CU, he joked that I obviously hadn't had a shower for a couple of days, as the RCD had tripped. Thing is, it had been working fine and only tripped out during his testing, didn't think much about it at the time but it seems to me know it should have tripped as soon as I tried to use the ring. Can you shed light on that?
Another question re RCD provision - do the new 2008 regs stipulate that a ring needs to be on RCD if you add a new socket, or does this apply only to new circuits?
Another question re RCD provision - do the new 2008 regs stipulate that a ring needs to be on RCD if you add a new socket, or does this apply only to new circuits?
the 2008 regs say that all general purpose sockets under 20A (which is what you have) require RCD protection.
The regs are not retrospective, so you are not required to add RCD to existing sockets, but the problem comes when you add any new work to an old circuit. How do you give RCD protection to the new wire and socket which you are adding to an old circuit?
Also, as mentioned above, there is a requirement to protect any new cables installed.
Usually, the easiest way to comply with this is install an RCD. This could be at the consumer unit, which will protect the whole circuit (old and new parts) or you could employ some other method, which may not be as easy or as cheap.
The regs are not retrospective, so you are not required to add RCD to existing sockets, but the problem comes when you add any new work to an old circuit. How do you give RCD protection to the new wire and socket which you are adding to an old circuit?
Also, as mentioned above, there is a requirement to protect any new cables installed.
Usually, the easiest way to comply with this is install an RCD. This could be at the consumer unit, which will protect the whole circuit (old and new parts) or you could employ some other method, which may not be as easy or as cheap.
Thinking about gradually replacing existing MCBs with RCBOs as I can afford it, starting with my cooker and ring mains - any experience of these?
That's a good idea.
Sockets first, particularly those used for outdoor tools and other appliances you can hold (if you have more than one socket circuit) that's the most important.
Sockets first, particularly those used for outdoor tools and other appliances you can hold (if you have more than one socket circuit) that's the most important.
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Yes.
Either it tripped out from the moment it was re-energised or the RCD is kaput or your version of events is a little muddled.
What were his test results?
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