U

uksparks

Hi,

Got called to a customer today, background is he has been doing some DIY... he had replaced a load of light fittings and plug sockets, he said we extended this one here and burried it in the wall etc... found one twisted together with tape, no connectors etc... anyway..

The problem is, since yesterday, he said the plugs downstairs don't work... hmmm

I plugged the socket tested in, beep beep beep beep beep, Earth and Live Reverse.... so i go to another, and get the same, then go to another, and its already beeping at me without switching the switch on, its a Fluke socket tester, first two are lit up, then switch it on then its just the first one so suggest Live earth reverse.

I then get the MFT out, plug it in at a socket,

Line to Neutral = 5.5v
Line to Earth = 230v
Neutral to Earth = 230v

Hmm, that's not right...

I pulled off all the face plates down stairs that I could that appears to be on that circuit one at a time thinking ill find the problem, but nope, nothing, all seemed in order (a mess but in the right holes). They said they did not extend or chop any circuits on the plugs, only the lights (they work fine).

Oh its a radial by the way.

So then the lounge, I took the faceplate off, left all conductors hanging (terminated in wagos) turned back on, same problem on sockets, but the ones he had changed were all dead, so im thinking must be somewhere else, put it back together.

Looked at the consumer unit, dual split board, a mess, blatant cowboy who fitted it, everything in the wrong places etc, but anyway, RCD protected. So the circuit was holding fine, as was the RCD.

I put a jumper between Line and Earth and then went round the sockets to get an R1+R2, all seemed pretty much in order, went round everything I could find, all seemed to be ok.

Then hooked Line to Neutral, went round the sockets, not a bloody sausage, nothing, not on any socket anywhere, nothing hooked off the circuit.

Then hooked Neutral to Earth and got a reading on everything.

So then I thought, well everything appears to be in the correct places so what the hells going on... I said it Friday night, I want to go home now thanks, and am going back next Tuesday and have left the circuit off.

My next step is to remove all faceplates on the circuit, so perhaps 15 say, then try to connect one at a time and see what happens.

Has anyone got a better suggestion as ill be honest, im stumped on this, I normally find these things quick and move on, but I spent 2.5 hours then this evening and couldn't work it out.

He assures me he has only changed Faceplates, only 4 of them down stairs in the lounge, you could see they were new. He has not touched anything else on the plug circuit.
 
Hi,

Got called to a customer today, background is he has been doing some DIY... he had replaced a load of light fittings and plug sockets, he said we extended this one here and burried it in the wall etc... found one twisted together with tape, no connectors etc... anyway..

The problem is, since yesterday, he said the plugs downstairs don't work... hmmm

I plugged the socket tested in, beep beep beep beep beep, Earth and Live Reverse.... so i go to another, and get the same, then go to another, and its already beeping at me without switching the switch on, its a Fluke socket tester, first two are lit up, then switch it on then its just the first one so suggest Live earth reverse.

I then get the MFT out, plug it in at a socket,

Line to Neutral = 5.5v
Line to Earth = 230v
Neutral to Earth = 230v


Hmm, that's not right...

I pulled off all the face plates down stairs that I could that appears to be on that circuit one at a time thinking ill find the problem, but nope, nothing, all seemed in order (a mess but in the right holes). They said they did not extend or chop any circuits on the plugs, only the lights (they work fine).

Oh its a radial by the way.

So then the lounge, I took the faceplate off, left all conductors hanging (terminated in wagos) turned back on, same problem on sockets, but the ones he had changed were all dead, so im thinking must be somewhere else, put it back together.

Looked at the consumer unit, dual split board, a mess, blatant cowboy who fitted it, everything in the wrong places etc, but anyway, RCD protected. So the circuit was holding fine, as was the RCD.

I put a jumper between Line and Earth and then went round the sockets to get an R1+R2, all seemed pretty much in order, went round everything I could find, all seemed to be ok.

Then hooked Line to Neutral, went round the sockets, not a bloody sausage, nothing, not on any socket anywhere, nothing hooked off the circuit.

Then hooked Neutral to Earth and got a reading on everything.

So then I thought, well everything appears to be in the correct places so what the hells going on... I said it Friday night, I want to go home now thanks, and am going back next Tuesday and have left the circuit off.

My next step is to remove all faceplates on the circuit, so perhaps 15 say, then try to connect one at a time and see what happens.

Has anyone got a better suggestion as ill be honest, im stumped on this, I normally find these things quick and move on, but I spent 2.5 hours then this evening and couldn't work it out.

He assures me he has only changed Faceplates, only 4 of them down stairs in the lounge, you could see they were new. He has not touched anything else on the plug circuit.

There's your answer Earth to neutral 230 volts you've lost a neutral some where and confirms it with live earth reverse on a socket tester not an accurate means of testing
 
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I did just this last week ..... far easier to get to the bottom of the issue, especially on a radial!
 
Well yes, ill be getting the wander lead out when I go back, I hadn't really got time to look to far into it as its Friday night and ive got better things to do live go on here LOL.

I will do as in post #4

Surely if you are getting 230v across Neutral and Earth, how can you have a lost neutral? Clearly there is one there as its got 230v across it.

Not only that you shouldn't get 230v across Neutral and Earth, so how do you explain that if the Neutral is lost?

Also, if you are saying its a lost neutral, how comes you don't have 230v from Line to Earth?

I tested this with my MFT to see, it clearly showed:

Line to Neutral = 5.5v
Line to Earth = 230v
Neutral to Earth = 230v

This is not readings from a socket tester. I only plugged the socket tester in to see if it was 'normal' so to speak. If you had no neutral you would not get 230v Neutral to Earth.

Am i being thick and missing the obvious or something?
 
No there's 230 volts to earth, meaning the neutral is not returning to the DB and beyond. As others have said wander lead test every cable.
 
Yes the readings we increasing as you would expect.

Dillb, you say its 230v to earth, I appreciate that, but if you are saying that the neutral is lost, i.e disconnected, broken, how can 230v go up the neutral and down the earth if its broken / disconnected somewhere?

Are you suggesting that the socket testing is wrong then? It clearly says the earth and line are reversed. Can you explain to me then how this is not the case?

I am trying to get my head around this in a logical manor but something inst clicking clearly.
 
Yes the readings we increasing as you would expect.

Dillb, you say its 230v to earth, I appreciate that, but if you are saying that the neutral is lost, i.e disconnected, broken, how can 230v go up the neutral and down the earth if its broken / disconnected somewhere?

Are you suggesting that the socket testing is wrong then? It clearly says the earth and line are reversed. Can you explain to me then how this is not the case?

I am trying to get my head around this in a logical manor but something inst clicking clearly.

There is obviously something plugged in that's not working, that puts voltage onto the neutral, which will then be shown on your tester.
 
First of all, check the neutral connection in the cu. Plug testers can be fooled.

Why do you get a belt from a disconnected neutral on a live circuit ?
 
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I'll go over Tuesday and sort it, Friday night is not the most ideal time to be fault finding. Something has clearly changed as he said he changed the 4 faceplates and then they wouldn't work... I'm not convinced.

enjoy your weekend.
 
I unplugged everything and also switched all FCU's off by the way. It will probably be obvious to me when I go back.
 
how can 230v go up the neutral and down the earth if its broken / disconnected somewhere?

230V doesn't go up or down anywhere, it exists at a point (any point) relative to another point.

Neutral is normally at 0 volts relative to earth ,ie. connected to earth, and live is at 230volts relative to neutral (and earth).

In your situation the connection to neutral has been broken at some point so everything which is the other side of the break will be effectively floating and not have any potential (voltage) relative to live or neutral. Except when a load is connected to the circuit, at which point the floating neutral wire becomes connected to live (via the load) and will therefore have a potential of 230volts relative to earth.
 
and its already beeping at me without switching the switch on
are they only switching 1 pole? Also re DIY, explain to customer (tactfully) that the longer it takes, the more it costs and if he can remember seeing 'someone' doing j.b's etc and where, it will save £'s, then the canary will sing!
 
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Yes it must be so single pole. I cannot believe thT he only changed three faceplates, it's not possible to create this problem.
 
230V doesn't go up or down anywhere, it exists at a point (any point) relative to another point.

Neutral is normally at 0 volts relative to earth ,ie. connected to earth, and live is at 230volts relative to neutral (and earth).

In your situation the connection to neutral has been broken at some point so everything which is the other side of the break will be effectively floating and not have any potential (voltage) relative to live or neutral. Except when a load is connected to the circuit, at which point the floating neutral wire becomes connected to live (via the load) and will therefore have a potential of 230volts relative to earth.

As everything was unplugged this is what is not helping, I'll let you know how I get on when I go back.
 

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