Problem this afternoon

[davesparks]

are you sure everything is unplugged and disconnected from the circuit? If a diyer has been at large then there could be anything connected to that circuit including lights, showers, cookers, next doors cat etc.

And what are you using to measure the voltage? an AVI? if not then you may be chasing a ghost voltage.

 

[Richard3009]

Wander lead and methodically go down each core, the broken circuit has to show.

 

[davesparks]

Wander leads? testing each core? what is this?

1- Split the circuit in half, find which half contains the fault.
2- split the faulty half in half again and find which half contains the fault.
3- split the faulty half in half again and find which half contains the fault.
...........
hey presto! you've found the fault.

 

[Richard3009]

If any load has been tapped off the ring and you have a broken neutral this problem would appear, you need to find where the neutral is open circuit

 

[uksparks]

I am confident everything was unplugged, I went through very room myself and made sure. I used my Fluke MFT to measure the voltage and twiddled the thing to switch it between conductors etc.

I split the ring in one place and it knocked out the room he claimed to have been messing with, the problem was still there, so therefore the problem must be somewhere else, either it's a whopping coincidence that it's gone funny when he changed the faceplates, or he is not telling me something...

 

[uksparks]

I see what you mean now about the neutral being broken and voltage going through the line to neutral then to earth.

 

[basejumper31]

Reading the above.. holy hell, what am I getting into training for this profession!! lol. Joking, I enjoy the challenge, but, wow, I can kinda see why this takes many years to get proficient at!

Good luck when you go back on Tuesday. Also nice to see such an active and helpful community!

(UkSparks hope you don't mind this off-topic comment.. I will ofc delete if you do)

Have a great wkend everyone.

 

[Richard3009]

Wander leads? testing each core? what is this?

1- Split the circuit in half, find which half contains the fault.
2- split the faulty half in half again and find which half contains the fault.
3- split the faulty half in half again and find which half contains the fault.
...........
hey presto! you've found the fault.

Radial circuit don't split it, just run wander lead from CU to each N connection until you lose continuity, then try to figure out the physical routing of cables and hunt down the nasty connection junction box or connector block

 

[davesparks]

Radial circuit don't split it, just run wander lead from CU to each N connection until you lose continuity, then try to figure out the physical routing of cables and hunt down the nasty connection junction box or connector block

Why use a wander lead? you have all the conductors you need already installed in the circuit.

I was explaining the method of fault finding any standard circuit, be it ring or radial.

In this case you can quite easily test voltage at each socket and identify where the neutral becomes broken without use of either wander lead or splitting the circuit. Where it's good there will be negligible voltage between N and E and nominal 230V between L and N, where its bad there will be nominal 230V between N and E and negligible V between L and N.

 

[davesparks]

I see what you mean now about the neutral being broken and voltage going through the line to neutral then to earth.

I don't think you do, the voltage is not going through anything. Voltage is a measure of the electrical potential at a point, it doesn't travel anywhere.

I am constantly amazed at the number of people who struggle with this concept, everybody learns this stuff at school yet nobody seems to understand!

 

[Richard3009]

True various methods, I like dead circuits though, they tell the truth.

 

[uksparks]

I think either method is going to work, just need to get back to it to sort it now.

I did try continuity of neutral and line connected and got zilch at every socket... Pain in the ---.

Now I'm armed with a few ideas, I should be able to locate it without too many issues.

 

[uksparks]

I don't think you do, the voltage is not going through anything. Voltage is a measure of the electrical potential at a point, it doesn't travel anywhere.

I am constantly amazed at the number of people who struggle with this concept, everybody learns this stuff at school yet nobody seems to understand!

I do get it, I just don't explain myself that well, I know it's a difference in potential, and know it doesn't go up one way and down the other.

 

[Richard3009]

Take your time and don't panic, you can always rewire it :cyclist:

 

[Richard Burns]

I did try continuity of neutral and line connected and got zilch at every socket... Pain in the ---.

If you got no continuity on all sockets then this points to the problem being before the sockets, try testing from the first socket (if you can tell where it is) to the later sockets and if all is OK then the problem is between the first socket and the CU. It does not have to be where the work was done, circuits can fail anyway (but may have been helped along by DIY)

 

[Badged01]

Bit late on a Friday night and the old speckled has gone down great guns so I might not be thinking too straight in my analysis but based on what your saying I reckon you have a L and E reversal problem ........

I plugged the socket tested in, beep beep beep beep beep, Earth and Live Reverse....

Wouldn't trust them to tell you what the problem is, just that you've potentially got a problem! But hey it might be right this time ...

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

If you have no loads applied when doing the tests (i.e. no L to N connection) this is telling me your earth is at 230V and Live & Neutral are at 0V ..... maybe your socket tester isn't lying and the E and L are reversed! Why didnt the RCD 'pop' on the tests? If so on which one?

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).

If all the sockets are wired correctly then you've got a problem elsewhere in the circuit ..... starting to think you've got a junction box or something somewhere crossing over the polarity? Assuming its not at the CCU? Somewhere between the CCU and 1st socket?

the ones he had changed were all dead

Is that dead L-N, L-E and N-E? If just L to N then they will be if you do have a L and E reversal. If dead across everything then there must be a break in the live feed but this would effect all the sockets unless they are the end of the radial! The plot thickens .....

So the circuit was holding fine, as was the RCD.

Was the RCD holding with loads applied (and working!) at the sockets? If so you cant have a L to E cross-over so my theory disappears!. If the breaker holds you ain't got a L to N cross-over either at any point. Whatever it is, its consistent and not just a single problem!

put a jumper between Line and Earth and then went round the sockets to get an R1+R2, all seemed pretty much in order,

As in every single socket? If so then you ain't got any single L to E problems but you could have a total L to E reversal!

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

Nope you wont have if the whole circuit L and E have been reversed!

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

Yep, you will have if the whole circuit L and E have been reversed

So then I thought, well everything appears to be in the correct places so what the hells going on...

They can't be for the results you've got, something is amiss somewhere in the circuit ... no sh*t Sherlock!

Does anything work when plugged in? If not you've got a L-E reversal, nothing will work! If it does work then I reckon you need to patent the circuit as you've discovered a new law to physics .....

 

[Engineer54]

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.

So you have left the customer without downstairs sockets until Tuesday?? Well your customer won't be enjoying their weekend then, will they!!

Not exactly the best approach for customer care, and i wouldn't blame the customer at all, if he called in another electrician to sort the problem out....

Fault finding on a radial socket circuit is a doddle, a methodical approach would have found the problem within the hour...

 

[Richard3009]

On a Friday night at beer o clock I would leave the whole house switched off. :driving:

 

[Silly Sausage]

So you have left the customer without downstairs sockets until Tuesday?? Well your customer won't be enjoying their weekend then, will they!!

Well, it was the householder mincing around with the electrics to begin with, so, tough -------!

 

[davesparks]

True various methods, I like dead circuits though, they tell the truth.

You what now? I don't understand?

What truth do dead circuits tell? and what untruths do live circuits tell?